averages of groups 2 and 3 were separated by a gap
greater than the selected critical gap size (Fig. 14).
2.-Peduncle; unigeniculate (rotation of hand less of
40°) (p), bigeniculate (rotation of hand more than 50°)
(a). 3.-Inner lamella; absent or rudimentary (p), well
developed (a). 4.-Spur of thumb; absent (p), present
(a). 5.-Apex of spur; not modified (p), modified (a).
6. Acute angle between thumb and spur; absent (p),
present (a). 7.-Dorsal margin of thumb; not spinose
(p), spinose (a). 8.-Dorsal margin of thumb; not crenate (p), crenate (a). 9.-Longcurved process on thumb;
absent (p), present (a). 10.- Teeth on finger; absent (p),
present (a). 11.-Proximal tooth; shorter than distal one
(p), bigger than distal one (a). 12.-Small tooth just at
proximal tooth; absent (p), present (a). B.-Apex of
finger; acuminate, not modified (p), modified (a). 14.Lateral blade on apex of finger; absent (p), present (a).
15.-Lateral blade on apex of finger; not undulate, nor
serrate (p), undulate, or serrate (a). 16.-Lateral spiniform structure on apex of finger; absent (p), present (a).
17. -Lateral knob-like protuberance on apex of finger;
absent (p), present (a). 18.-Ventral blade on apex of finger; absent (p), present (a). 19.-Linguiformgenitaloutgrowths; absent (p), present (a). 20.-Cercopods; setose
(p), spinose (a). 21.-0varies; uniramous (p), biramous
(a). 22.-Laterallamella of thumb; absent (p), present
(a). 23. Small tooth just at distal tooth; absent (p),
present (a). 24.-Dorsal margin of antennule; smooth
(p), crenate (a). 25. Dorsal digitiform outgrowths on
peduncle; absent (p), present (a).
Streptocephalidae Daday, 1910
Streptocephalus Baird, 1852
Remark. We recognize 13 New World species, which
represent only three of the nine species groups of the
genus (Maeda-MartInez et aI., 1995; this volume), i.e.
the dendyi group, dendyi subgroup, with only one
species, the sealii group with three species, and the
torvicornis group, torvicornis and mackini subgroups,
with two and seven species, respectively.
dendyi group; dendyi subgroup
Streptocephalus kargesi Spicer, 1985
(Fig. 1 A-E)
Streptocephalus kargesi Spicer, 1985; MaedaMartInez, 1991.
17
Type material. Holotype and paratypes USNM
204931-32.
Type locality. 11.3 km S of Lago Catemaco, El Encinal, Veracruz, Mexico.
Material examined. Paratypes USNM 204932, 1 d'
12.5 mm (used for SEM), 1 d' 13.7 mm, 2 Q Q 14.0,
14.0mm.
Diagnosis. Male. Peduncle of distal outgrowth of short
type; no spur on thumb; no teeth on finger; frontal
appendage simple, short and rounded at tip; peduncle
with pulvinus; thumb with lateral lamella, of which
anterior border extends obliquely to near base of finger;
inner lamella rudimentary; distal part of thumb inerm
(= without spines), not geniculate, its apex acuminate;
distal part of finger inerm, not geniculate, but slightly curved in dorsal direction, apex acuminate; genitalia without linguiform outgrowths; cercopods setose
along inner and lateral borders; anus terminal.
Female. Ovaries uniramous; cysts sphaerical, ornamented by well developed ribs forming polygonal
areas.
Differential diagnosis. S. kargesi appears to be one
of the simplest Streptocephalus. The presence of a laterallamella on the hand (Fig. 1 B), the absence of linguiform genital outgrowths (Fig. 1 D), and the setose
cercopods (Fig. 1 E) are characteristics which differentiate S. kargesi from all other species of the subgroup.
The Africans S. dendyi, and S. purcelli Sars, 1898,
have a pair of linguiform outgrowths and spinose cercopods, and no lateral lamella on the hand (Sars, 1898;
Daday, 1910; Barnard, 1929).
Distribution. S. kargesi is known only from the type
locality.
sealii group
Streptocephalus sealii Ryder, 1879
(Fig. 2 A-E)
Streptocephalus sealii Ryder, 1879; Packard, 1883;
Daday, 1910; Creaser, 1930; Linder, 1941; Brtek,
1974. S. sea Ii Mackin, 1942; Moore, 1958, 1966;
Dexter, 1959; Belk, 1975; Spicer, 1985; Pennak, 1989;
Maeda-MartInez, 1991. (?) S. fioridanus Packard, 1880
(see Creaser, 1930. S. coloradensis Dobbs, 1915. S.
americanus Pesta, 1921.
Type material. Moore (1966) reported that some of
the type specimens are deposited in the Academy of
greater than the selected critical gap size (Fig. 14).
2.-Peduncle; unigeniculate (rotation of hand less of
40°) (p), bigeniculate (rotation of hand more than 50°)
(a). 3.-Inner lamella; absent or rudimentary (p), well
developed (a). 4.-Spur of thumb; absent (p), present
(a). 5.-Apex of spur; not modified (p), modified (a).
6. Acute angle between thumb and spur; absent (p),
present (a). 7.-Dorsal margin of thumb; not spinose
(p), spinose (a). 8.-Dorsal margin of thumb; not crenate (p), crenate (a). 9.-Longcurved process on thumb;
absent (p), present (a). 10.- Teeth on finger; absent (p),
present (a). 11.-Proximal tooth; shorter than distal one
(p), bigger than distal one (a). 12.-Small tooth just at
proximal tooth; absent (p), present (a). B.-Apex of
finger; acuminate, not modified (p), modified (a). 14.Lateral blade on apex of finger; absent (p), present (a).
15.-Lateral blade on apex of finger; not undulate, nor
serrate (p), undulate, or serrate (a). 16.-Lateral spiniform structure on apex of finger; absent (p), present (a).
17. -Lateral knob-like protuberance on apex of finger;
absent (p), present (a). 18.-Ventral blade on apex of finger; absent (p), present (a). 19.-Linguiformgenitaloutgrowths; absent (p), present (a). 20.-Cercopods; setose
(p), spinose (a). 21.-0varies; uniramous (p), biramous
(a). 22.-Laterallamella of thumb; absent (p), present
(a). 23. Small tooth just at distal tooth; absent (p),
present (a). 24.-Dorsal margin of antennule; smooth
(p), crenate (a). 25. Dorsal digitiform outgrowths on
peduncle; absent (p), present (a).
Streptocephalidae Daday, 1910
Streptocephalus Baird, 1852
Remark. We recognize 13 New World species, which
represent only three of the nine species groups of the
genus (Maeda-MartInez et aI., 1995; this volume), i.e.
the dendyi group, dendyi subgroup, with only one
species, the sealii group with three species, and the
torvicornis group, torvicornis and mackini subgroups,
with two and seven species, respectively.
dendyi group; dendyi subgroup
Streptocephalus kargesi Spicer, 1985
(Fig. 1 A-E)
Streptocephalus kargesi Spicer, 1985; MaedaMartInez, 1991.
17
Type material. Holotype and paratypes USNM
204931-32.
Type locality. 11.3 km S of Lago Catemaco, El Encinal, Veracruz, Mexico.
Material examined. Paratypes USNM 204932, 1 d'
12.5 mm (used for SEM), 1 d' 13.7 mm, 2 Q Q 14.0,
14.0mm.
Diagnosis. Male. Peduncle of distal outgrowth of short
type; no spur on thumb; no teeth on finger; frontal
appendage simple, short and rounded at tip; peduncle
with pulvinus; thumb with lateral lamella, of which
anterior border extends obliquely to near base of finger;
inner lamella rudimentary; distal part of thumb inerm
(= without spines), not geniculate, its apex acuminate;
distal part of finger inerm, not geniculate, but slightly curved in dorsal direction, apex acuminate; genitalia without linguiform outgrowths; cercopods setose
along inner and lateral borders; anus terminal.
Female. Ovaries uniramous; cysts sphaerical, ornamented by well developed ribs forming polygonal
areas.
Differential diagnosis. S. kargesi appears to be one
of the simplest Streptocephalus. The presence of a laterallamella on the hand (Fig. 1 B), the absence of linguiform genital outgrowths (Fig. 1 D), and the setose
cercopods (Fig. 1 E) are characteristics which differentiate S. kargesi from all other species of the subgroup.
The Africans S. dendyi, and S. purcelli Sars, 1898,
have a pair of linguiform outgrowths and spinose cercopods, and no lateral lamella on the hand (Sars, 1898;
Daday, 1910; Barnard, 1929).
Distribution. S. kargesi is known only from the type
locality.
sealii group
Streptocephalus sealii Ryder, 1879
(Fig. 2 A-E)
Streptocephalus sealii Ryder, 1879; Packard, 1883;
Daday, 1910; Creaser, 1930; Linder, 1941; Brtek,
1974. S. sea Ii Mackin, 1942; Moore, 1958, 1966;
Dexter, 1959; Belk, 1975; Spicer, 1985; Pennak, 1989;
Maeda-MartInez, 1991. (?) S. fioridanus Packard, 1880
(see Creaser, 1930. S. coloradensis Dobbs, 1915. S.
americanus Pesta, 1921.
Type material. Moore (1966) reported that some of
the type specimens are deposited in the Academy of