ASTACID^E. 73 



excision ; the example is otherwise similar to C. immunls ; nevertheless, 

 it possibly belongs to a different species. 



C. minimis is a very interesting species; by its conical, short, and 

 toothless rostrum it is allied to the group of C. Bartonii, by the ab- 

 dominal legs of the male to the group of C. affinis. I have not seen 

 young specimens ; they, perhaps, possess lateral spines. 



Cat, No. 188, Lawn Ridge, 111., Mr. C. Ordway. Male. Fem. Spec. 5. 



Cat. No. 1841, Belleville, 111. Male. Spec. 1. 



Cat. No. 301, Huntsville, Ala. Male. Spec. 1. 



Cat. No. 1842, Beaufort, N. C, Mr. Bickmore. Fem. Spec. 1. 



23. Cambarus extraneus Hagen. 



Figures on PL I. and III. 



First abdominal legs of the male : 



second form, fig. 88 in front ; fig. 89 outside. 



Antennal lamina, fig. 156, a; epistoma, b ; spine of the second joint of the exterior an- 

 tenna, c. 



Mas. Bostro lato, duplo vel triplo-longiori, lsevi, excavate, margini- 

 bus pimctato-lineatis, subparallelis vel subconvergentibus, utrinque ad 

 apicem fortiter sinuatis; acumine longo, acute, utrinque , dente brevi, 

 acute ; cretis parum elevatis, parallelis, sulcatis, spina acuta antica. 

 Antennis validis (basis moclo exstat), articulis duobus basalibus dente 

 externo acute, antennis internis articulo basali dente infero acute ; la- 

 mina rostri longitudine, modice lata, margine externo late inflate, apice 

 spina acuta longiori. Epistomate brevi, lato, antice obtuso, rotundato, 

 angulis lateralibus acutioribus ; pedibus maxillaribus externis intus 

 barbatis. Thorace leviter ovate, densius punctato-ciliato, lateribus 

 granulosis, scabris; linea profunda, subfissa, utrinque spina valida acuta; 

 spina antica infera ad antennarmn basin ; areola lata, plana, punctata, 

 antice posticeque paulo clilatata, cephalothorace margine antico ad basin 

 antennarum loco anguli dente parvo acute. Postabdomine thoracis lati- 

 tudine, paulo longiori, parce punctato, segmentis antepenultimis angulo 

 laterali subrecto ; lamina intermedia utrinque bispinosa, parte apicali 

 breviori, rotunclata. Pedibus anticis modicis ; chela magna, lata, depres- 

 sa, densius punctato-ciliata ; margine interno longo, subrecto, biseriatim 

 tuberculato-dentato ; digitis validis, planis longioribus, costato-lineatis, 

 intus dentatis, basi subtus barbatis. Carpo lato, oblique truncate, parum- 

 punctato, spina interna media majori, aliaque basali brevi; subtus spinis 

 duabus anticis validis. Brachio longiori, laevi, spinis duabus anteapicali- 

 bus validis, oblique positis, subtus spinis acutis biseriatis, spina ad arti- 

 culationem utrinque valida. Pedibus tertiis articulo tertio unguiculato ; 

 pedibus quartis capitulo basali ovato, parvo. (Forma I. mihi in visa.) 



Forma II. Pedibus abdominalibus basi articulatis, validis, brevibus, 

 contortis ; parte interna cylindrica, brevi, apice acutiori recurva ; parte 



10 



