REVISION OF SJMOCEPHALUS DAPHNIIDAE 
ETYMOLOGY. The name ‘Echinocaudus’ is derived from the words 
‘echinus’ — ‘hedgehog’ and ‘cauda’ — ‘tail’ and refers to the pecten of 
spines at the base of postabdominal claw that is typical of this 
subgenus. 
S. obtusatus (Thomson, 1878) 
Fig. 31 
Daphnia obtusata Thomson, 1878: 261; Simocephalus obtusatus: 
Sars, 1894. 
TYPE MATERIAL. No information. Type locality: New Zealand, 
Dunedin. 
MATERIAL EXAMINED. 
Henry: 9 ad. (AM, 7182). 
DIAGNOSIS. Measurements. 9 9 ad.: 2.0-2.5mm,c"o": 1.0—1.2mm. 
Both sexes. Frons rounded (Fig. 31D). Ventral head margin very 
convex. Rostrum short. Setules on inner side of posterior valve 
margin slender. Dorso-posterior valve angle without prominence 
(Fig. 31A,F). One supra-anal angle (Fig. 31E). Basal pecten of 
postabdominal claw with 10-12 large well-spaced spines (Fig. 
31C). Size of spines maximal in middle. 
(Fig. 32) New Zealand. 
New Zealand, Lake Takapuna, leg. 
DISTRIBUTION. 
REMARKS. The original description was provided with an illustra- 
tion and shows that S. obtusatus differs markedly from all other 
21 
species in head shape (Thomson, 1878). The most detailed descrip- 
tion of the female and the first description of the male was given by 
Sars (1894). 
S. daphnoides Herrick, 1883 
Fig. 33 
Simocephalus daphnoides Herrick, 1883: 503; S. Iheringi Richard, 
1897: 279 syn. nov.; S. fonsecai Bergamin, 1939: 82 syn. nov.; S. 
fonsecai var. sinucristatus Bergamin, 1939: 84 syn. nov. 
TYPE MATERIAL. Probably the types were not indicated by Herrick 
as in the case of other species described by this author (D. Frey, 
personal communication through N.N. Smirnov). Type locality: 
U.S.A., Alabama, Decatur. 
MATERIAL EXAMINED. Argentina, Rio Parana, Catay pond, 1973, 
leg. Frutos: 39 Qad., 39 Qjuv. (AC). Peru, vicinity of Pucalpa, 
pond near Ucayali river, 2. 1987, leg. Pegasov: 42 Q ad. (AC). 
DIAGNOSIS. Measurements. 2 9 ad.: about 1 mm. 
Female. Frons rounded (Fig. 33). Ventral head margin concave, 
straight or with small prominence. Rostrum short. Setules on inner 
side of posterior valve margin slender. Dorso-posterior valve angle 
with large, pointed prominence. One supra-anal angle. Basal pecten 
of postabdominal claw of 20-30 small, close-set spines of equal 
length. 
Male unknown. 
Lee 
NAS 


\ 
> 
@ S. vetulus Os. mixtus 
© S. gibbosus @S. elizabethae 
® S. punctatus 
© S. vetuloides & S. mixtus 
" 
: 

Os. vetulus & §S. mixtus 
@s. elizabethae & S. gibbosus 
MS. vetuloides 
Fig. 21 Locations, where studied material of Simocephalus s. str. was collected. 
