ASTACIDJ^. 55 



parte apicali aiitieo rotundata (? margo doest). Podibus anticis niodi- 

 cis. dense squainoso-tuI)eieidatis ; chela latiuscula, modice iiiHata, ubiqiie 

 squamoso-tubereulata, margine interno recto serrato; digitis \ alidis, rec- 

 tis, costatis et punctato-lineatis, extus squamoso-tuberculatis, intus den- 

 tatis. tuberculis basalibus validioril)us. Carpo sqiiamoso-tvi])eroulato, 

 iiiargine interno dentuto ; subtus spinis duabu.s anticis. Brachio kevi, 

 snpra et antice tubercnlato, subtus biseriatim dentato. Ventre inter 

 pedes quartos nudo, annulo niajori, obovato, indiviso, antice subexciso, 

 medio transverso-elevato, postice depresso. 



Long. 2.G ; antenn. ; ped. ant. 1.7. 



Hab. : Mexico. Acad. N. Sc. Philadelphia. 



I have seen only one female, which was found by Mr. Pease. Pro- 

 fessor Erichson has described a little smaller male (two inches long) ; 

 the description agrees very well. Erichson remarks that the third 

 pair of legs and the fourth possess a hook. 



This species is apparently of the same group as C. penicillatus. It 

 differs in the strongly- tuberculated hands, the much enlarged lamina 

 of the antenna?, and the small areola. This species and A. pellucidus 

 have the lamina of the antennte most dilated near the tip, all other 

 species of this group have the greatest dilatation behind the middle 

 and nearer the base. 



Cambarus Aztecus Saussure, Revue et Magas., T. 9, p. 503, and Mem. 

 Soc. Phys. Geneve, T. 14, P. II. p. 4G0, fig. 23, from Tomatlan (ruis- 

 seaux dans les Terres-Chandes), seems to be identical with C. Wieffmanni, 

 at least with the female described by me. 



13. Cajibarus pellucidus Tellhampf. 



Astacus pellucidus ToUkampf, Mueller Archiv. 1844, p. 383. — Erichson, Wiegin. Arcliiv., 



T. 12, p. 95, n. 14. 



Figures on PI. I., III., and VI. 

 First abiloininal legs of the male : 



first form, fig. 68 in front, fig. 69 outside. 



second form, fig. 70 in front, fig. 71 outside. 

 Antennal lamina, fig. 148, o; epistoma, 6 ; spine of the second joint of the exterior antenna, c. 



Mas. Rostro lato, longo, Itevi, subexcavato, foveola basali, latiori, 

 marginibus modice elevatis, subconvergentibus, utrinque valde excisis, 

 spina valida, acuta, subrejecta ; acumine longo, angusto, acuto ; cretis 

 perparvis, fere parallelis, extus impressis, antice spina valida acuta. 

 Antennis corpore longioribus, articulis duobus basalibus dente externo 

 valido ; articulo basali internarum dente infero subapicali acuto ; lamina 

 rostro fere longitudine, sat lata, ante apicem latiori ; margine externo 

 paulo rotundato, inflato, spina apicali acuta. Epistomate brevi, lato, 

 subexcavato basi vix angustiori obtuse triangulari, dente medio antico 

 interdum producto. Pedibus maxillaribus externis intus barbatis. 



