56 ASTACID^. 



Thorace fere cylindrico ; mesotliorace longiori, postice paulo angustiori ; 

 parce pimctato, la3vi, lateribus subgranulosis ; cephalotliorace utrinque 

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

 riun acutarum, spinaqiie acuta antica infera ad antenuarum basin ; 

 areola sat lata, plana, lajvi. Postabdomine latitudine tlioracis, compresso, 

 laevi, apice non angustiori, angulis segmentorunx extemis 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, mai'gine 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 membrauacea, 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, aj^ice ob- 

 tusis, nee corneis. 



Femiua diflert clielis 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 ^oung. 



The Museum possesses a fidl-growu 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-fonn 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 ai'e entirely wanting. This 

 observation justifies me, perhaps, in placing C. i)ellucidm as the last 

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

 C. affinis. 



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

 Spec. 12.* 



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

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



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



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

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



