56 ASTACIDvE. 



Horace fere cylindrico ; mesothorace longiori, postice paulo angustiori ; 

 paree punctate, laevi, lateribvis subgranulosis ; cephalothorace utrinque 

 spinis nonnullis acutis; linea profunda, nun sinuata, serie postica spina- 

 rum acutarum, spinaque acuta antica infera ad antennarum basin ; 

 areola sat lata, plana, laevi Postabdomine latitudine thoracis, compresso, 

 laevi, apice non angustiori, anguJis segmentorum externis rectis; lamina 

 media parte apieali longa elliptica. parte basab apice utrinque bispinosa. 

 Pedibus anticis longis gracilibus, chela longa, angusta, depresso-cylin- 

 drica. subpunctata, margine interne longo. recto, dentato ; margine ex- 

 terno subdeutato ; digitis vix longioribus, rectis, gracilibus, subcostatis, 

 basi subdentatis. Carpo longo, subcylindrico. intus tuberculato, spina 

 media acuta; subtus spinis duabus anticis acutis, serie interna tubercu- 

 losa. Brachio longo. margine supero tuberculoso, spinis duabus ante- 

 apicalibus, oblique positis ; subtus spinis acutis biseriatis. Pedibus 

 tertiis et quartis articulo tertio uuguiculato; pedibus quartis capitulo 

 basab compresso, dilatato. Pedibus abdominal ibus modicis, rectis. apice 

 contortis; parte interna fortiori, cylindrica. apice membranacea. triangu- 

 lari. acuta, subincurva : parte externa vix breviori. apice cornea, subre- 

 curva, triangulari. Oculis occultis, cornea parva. indivisa. 



Forma II. Pedibus abdominalibus basi articulatis, similibus, apice ob- 

 tusis. nee corneis. 



Femiua differt chelis minoribus ; ventre inter pedes quartos nudo, 

 anuulo rotundato. clauso, medio carinato. 



Long. corp. 2.6 and 3.2; antenn. 3.2 and 3.4; ped. ant. 2.1. 



Hah. : Mammoth Cave. Kentucky. 



I have seen thirty-eight specimens, old and young. 



The Museum possesses a full-grown female of C. Bartonn, with the 

 eyes well developed, found in the Mammoth Cave. 



I have given the peculiarities of this abnormal species in the intro- 

 duction to this genus. I remark that in the second-form males the 

 abdominal legs are often not articulated, and that the hooks on the 

 third and the fourth set of legs are less developed. I have seen a 

 few specimens with the hooks on the fourth pair of legs much less 

 developed; in one specimen, even, they are entirely wanting. This 

 observation justifies me, perhaps, in placing C. peUucidus as the last 

 species of this group, and as somewhat allied to the following group of 

 ('. affirds. 



Cat No. 103. Mammoth Cave, Kentucky. Male Form I. and II. Fein. 

 Spec. 12* 



Cat. No. 225. Mammoth Cave, Kentucky, Professor Baird. Male 

 Form I. and II. Fern. Spec. 12* 



Cat. No. 1S2G. Mammoth Cave, Kentucky. Male. Fem. Spec. •">. 



Cat. No. 1S27. Mammoth Cave. Kentucky. Male, very large. Spec. 1. 



Dry Spec. Mammoth Cave. Kentucky. Male. Fem. Spec. 2. 



