﻿NORTH AMERICAN NOTOSTRACA — LINDER 49 



Remarks. — This new species is especially interesting, because it 

 belongs (see table 3) with L. bilohatus in the gi-oup with many abdom- 

 inal rings. The variation of the species, as limited above, may 

 perhaps seem to be rather gi'eat. It includes forms with a very 

 spiny carapace together with forms where the carapace is quite 

 smooth; but intermediate forms occur in great numbers, and we find 

 a similar variation in several species of the genus Ajaus (Barnard, 

 1929). Furthermore, the form of the supra-anal plate is highly 

 variable; but, as I have shown previously (p. 26), this is true of many 

 species. The great range of variation must be seen in connection 

 with the fact that the species is described from such a great number of 

 specimens from the same district. 



The species is easily distinguished from L. bilohatus by the size and 

 place of the nuchal organ and the eyes, characters to which I must 

 ascribe great taxonomic importance. Its relation to the following 

 form, however, I cannot regard as quite clear. 



LEPIDURUS LYNCHI ECHINATUS, new variety 



Figure 28; Plates 5 (Figure 1), and 7 (Figure 4) 

 Type specimens. — Holotype 9 (U.S.N.M. No. 82068), allotype cT 

 (U.S.N.M. No. 82069), paratypes 6 cf and 4 9 (U.S.N.M. No. 82070 

 and Uppsala Mus.). North end of Goose Lake, about 15 miles 

 southwest of Lakeview, Lake County, Orcg. ; altitude 4,700 feet; in 

 water 2 feet deep, muddy; June 14, 1940; collector, J. E. Lynch. 



Figure 28. — Dorsal view of telson and last two body-rings of a female of Lepidurus lynchi 

 echinatus, new variety, X 9. {S, dorsal sensory setae.) 



Body-rings 11 4- (16-17.5) + (3.5-4.5) =31-33. Telson rather long. 

 Always many large spines on carina of carapace. In females, 2-5 

 dorsal spines on supra-anal plate, in males, 3. Legs 67-68 in number 

 (only two specimens). Total length, disregarding supra-anal plate 

 and caudal filaments: Female 32-41 mm., male 22-30 mm. Length 

 of carapace: Female 21-28 mm., male 17.5-21 mm. Width: length 

 relation of carapace 1.21-1.29. 



956651—52 4 



