56 ASTACID.ZE. 



Thorace fere cylindrico ; mesothorace longiori, postice paulo angustiori ; 

 parce pimctato, lasvi, lateribus subgranulosis ; cephalothorace utrinque 

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

 rum acutarum, spinaque acuta antica infera ad antennarum basin ; 

 areola sat lata, plana, lsevi. Postabdomine latitudine thoracis, compresso, 

 lsevi, apice non angustiori, angulis segmentorum externis rectis ; lamina 

 media parte apicali longa elliptica, parte basali apice utrinque bispinosa. 

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

 drica, subpunctata, margine interno longo, recto, dentato ; margine ex- 

 terno subdentato ; 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 unguiculato; pedibus quartis capitulo 

 basali compresso, dilatato. Pedibus abdominalibus 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. 



Femina differt chelis minoribus ; ventre inter pedes quartos nudo, 

 annulo rotundato, clauso, medio carinato. 



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



Hab. : Mammoth Cave, Kentucky. 



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



The Museum possesses a full-grown female of C. Bartonii, 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. pellucidm as the last 

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

 C. affinis. 



Cat. No. 193, Mammoth Cave, Kentucky. Male Form I. and II. Fern. 

 Spec. 12 * 



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

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



Cat. No. 1826, Mammoth Cave, Kentucky. Male. Fern. Spec. 5. 



Cat. No. 1827, Mammoth Cave, Kentucky. Male, very large. Spec. 1. 



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



