36 \ REVISION OF THE ASTACID.E. 



Length. 62 nun. Rostrum, 6 mm. Carapace, 30 mm. From tip of ros- 

 trum to cervical groove, 19.5 mm. ; from cervical groove to posterior border 

 of carapace, 10.5 mm. Abdomen, 32 mm. Width of areola, 7 mm. Antennae, 

 47 mm. Chelipeds, 49 mm. Chela, 23 mm. Width of chela, 6 mm. 



St. John's River, Hawkinsville, Orange Co., Fla. : J. A. Allen. 



A well-marked species with toothless excavated rostrum (younger speci- 

 mens probably have marginal rostral teeth), narrow areola, long, sub- 

 cylindrical chelipeds covered with ciliated squamous tubercles. The first 

 abdominal legs are not jointed, the hooks on the third and fourth pairs 

 of thoracic legs are large and well finished, so that I consider the single 

 specimen examined to be the first form. 



In the collection of the Academy of Natural Sciences of Philadelphia 

 is a specimen from Hernando Co., Fla., Jos. W. Wilcox, which is probably 

 the second form of the male of this species. The sexual appendages are 

 not articulated at the base. The hooks on the third and fourth pairs of 

 legs are small, tooth-like processes merely. Besides the differences in these 

 hooks and in the sexual appendages, the following may be pointed out : 

 the rostrum has small lateral teeth near the tip, the post-orbital ridges have 

 a sharp spine at their anterior end, the basal segment of the fifth pair of 

 legs is armed with a sharp hooked tooth in place of a flattened tubercle, and 

 the hind segment of the telson is longer in proportion to its width. 



13. Cambarus penicillatus. 



dslacus penicillatus, Le Conte, Proc. Acad. Nat. Sci. Phila , VII. 101, 1855. 



Cambarus penicillatus, Hagen, 111. Cat. Mus. Comp. Zoo]., No. III. p. 53, PI. I. figs. 93, 91, [95, 96?], PL 



III. 6g. L49, 1870. 

 Cambarus penicillatus, Faxon, Proc. Amer. Acad. Arts and Sci., XX. 13S, 188 I 



Known Localities. — Georgia. Eastern Mississippi [?]. Charleston, S. C. [?]. 



None of Le Conte's types of this species are known. Of the specimens in 

 the Museum of Comparative Zoology referred to this species by Dr. Hagen. 

 a small male of the first form, from Georgia (No. 270). agrees well with Le 

 Conte's description. It has a small branchiostegian spine, overlooked in 

 Hagen's description. The rostrum has no trace of ante-apical spines; the 

 antennal scale is very broad, attaining its greatest breadth in the middle, 

 then narrowing but little until reaching the level of the apical spine. It 

 is a little shorter than the peduncle of the second antenna', and equal to 

 the rostrum in length. The male appendages are represented 01) Plate !■ 



