ASTACIDiE. 87 



Habitat : Charleston, S. C. ; Georgia ; Mobile, Ala. 



I have seen male ami female. 



This species is remarkable for the lateral lamina of the postabdomen. 

 In the allied species the middle rib terminates in a spine before the mar- 

 gin ; in this species the rilj ends exactly on the margin, and the spine 

 is acute and marginal. 



I have compared a female type in the Philadelphia Musemn. Tliis 

 is the largest specimen I have seen. 



It differs from the C. Carolimis in the short and anteriorly dilated 

 lamina of the antenna, with a short external spine ; in the teeth of the 

 first joint of the interior antennae, in the anterior spine at the end of the 

 thoracic line. In the larger specimens the hand is more sulcated beneath 

 at the inner margin, and the carpus more spinulose. 



I have seen many young specimens, but only one very young male 

 of the second form. The abdominal legs are in their first stage of de- 

 velopment. The tip is cylindrical, simple, and a little incurved. 



Cat. No. 282, Georgia, Dr. Jones. Male. Fem. Spec. 6. 



32. Cambarus Carolinus Erichson. 



Cambarus CaroUnus Erichson, Wiegm. Arch., T. 12, p. 96, n. 16. 



Figures on PI. I. and III. 



First abilominal logs of the male : 



first form, fig. 51 in front; fig. 52 outside. 



second form, fig. 53 in front; fig. 54 outside. 

 Antcnnal lamina, fig. 1G5, a; epistoma, 6; spine of the second joint of the exterior antenna, c. 



Mas. Rostro longiori, lato, triangulari, antice deflexo, excavato, 

 parce punctato, serie punctorum marginali, marginiljus elevatis ad 

 acuminis acuti apicem iion interruptis; cretis parvis, sulcatis, antice 

 muticis, subdivergentibus, postice callosis, convergentibus. Antennis 

 gracililjus, thorace paulo longiori1)us, dentibus articulorum basalium 

 nullis ; lamina parva, angusta, margine externo infiato, spina apicali 

 lono-iori. Epistomate lato, antice obtuso triangulari, lateribus obliquis, 

 subsinuatis ; pedibus maxillaribus exteniis intus barbatis. Thorace com- 

 presso, supra subdepresso, sparsim sed profunde punctato, lateribus 

 granulosis ; linea profunda, sinuata, laterilnis fissa, spina antica infera 

 nulla ; areola angusta, plana, media subnulla, lineari, postice triangulari 

 majori punctata. Postabdomine angusto, thorace sublongiori, parce 

 punctato ; segmentis antepenultimis angulis lateralibus rotundatis ; la- 

 mina media utrinque bispina, parte apicali breviori, rotundata. Pedibus 

 anticis brevibus, latis, chela brevi, lata, subintlata, paulo lanuginosa, punc- 

 tata ; margine interno curvato, serrato dentato, subtus sulcato ; margine 

 externo obsolete dentato ; digitis fere jequalibus, validis, nee longiori- 

 bus, rectis, costatis, lineato-punctatis, intus tuberculato-dentatis ; digito 

 mobili basi extus tuberculato. Carpo lato, oblique truncato, parce punc- 



