20 
M.J. ORLOVA-BIENKOWSKAJA 

“Te 

Fig. 20 Statistical analysis of ten series of Simocephalus s. str. from East Siberia and Far East. 1-7 — S. vetuloides, 8-10 — S. mixtus. A, result of cluster 
analysis, B, C, diagrams of characters. 
China (Stingelin, 1904), India (Biswas, 1971), Niger (Dumont & 
Van De Velde, 1977a), Nepal (Dumont & Van De Velde, 1977b), 
Central Asia (Manujlova, 1964). But judging from illustrations, 
these authors had specimens not of S. elizabethae but of S. mixtus. 
REMARKS. The original description (King, 1853a) contains the 
characters of two species. The first adequate description of this 
species was made by Sars (1888). Schddler (1877) and Negrea 
(1983) suppose S. elizabethae to be a synonym of S. vetulus. 
Dumont (1983) regards it as a subspecies of S. vetulus. I believe S. 
elizabethae to be a separate species, because it differs from S. 
vetulus in the shape of the ventral head margin and dorso-posterior 
valve prominence. These differences are not less than the differences 
between other species within this subgenus. 
Judging from the original description (Smith, 1909), the Tasma- 
nian species S. dulvertonensis belongs to Simocephalus s.str . 
Information about the type material is lacking. Available specimens 
from Tasmania differ slightly from Australian material in the shape 
of the dorso-posterior valve prominence, but this difference is 
insufficient to assign them to a separate species or subspecies. I 
agree with Brehm (1953) and Dumont (1983), that S. dulvertonensis 
is a synonym of S. elizabethae. 
Subgenus S. (Echinocaudus) subgen. nov. 
TYPE SPECIES. Simocephalus exspinosus (De Geer, 1778). 
DIAGNOSIS. Both sexes (Figs 28; 29). Frons rounded or pointed, 
without denticles. Head shield without depression. Head pores 
present. Insertion of antennules at base of rostrum. Antennule long 
or short in correspondence with long or short rostrum, with neither 
ridges nor denticles on inner side. Aesthetes longer than base of 
antennule. Postabdominal claw with basal pecten of spines at outer 
side. Inner side and distal part of outer side with fine setules. Anal 
bay of postabdomen narrow, rounded, with anal teeth. 
Female. Dorso-posterior valve angle with rounded prominence or 
without it. Valves without dorsal keel. Posterior commer of ephippium 
without protuberance. Ocellus short. Setae of 2nd and 3rd endite 
prominence of 2nd trunk limbas long as 0.7 and 1.1 of basal segment 
of plumose seta of Ist prominence respectively (Fig. 30B). 
Postabdomen with 9-22 anal teeth on each side (Fig. 28C). Supra- 
anal angle rounded. 
Male. Supra-anal angle rounded (Fig. 29). Vas deferens opening near 
its base. Postabdomen with 5-6 anal teeth on each side. Dorso- 
posterior valve angle with rounded or pointed prominence. 
