122 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



and having slenderer fore tibia, and in general the body and links are slenderer than in the species 

 of Trechus. But, remarks Bedel (in'Liste gen. des articubis cavernicoles de FEurope, p. 32): 



Les norubreuses de"convertes qu'ont amenees, depuis quelques aunees, les explorations des grottes, eelles de 

 1'Ariege principalement, out necessite" la reunion des Anophthalmias et Aphsenops aveugles aux Trechus ocul6s.* 

 C'est a peine si l'on doit les maintenir actuellement a titre de sous-genres, tous les passages existant entre ces types 

 extremes qui semblaient tout d'abord si nettement caract6ris6. 



Bedel obviates the inconvenience of placing between one and two hundred species into one 

 genus by retaining Anophthalmus as a subgenus of Trechus. It seems reasonable, then, so long 

 as most of the species of Anophthalmus are both eyeless and very slender in body and limbs, to 

 retain it under a distinctive name. 



In some other coleopterous genera the distinctive characteristic appears to be chiefly the lack 

 of eyes. Thus in Le Coute and Horn's Coleoptera of North America Adranes and Eutyphlus are 

 defined thus: "Eyes wanting." 



The eyeless genus of spiders, Anthrobia, is accepted as a distinct genus. Simon remarks : 

 "LAnthrobia pr6sente presque tous les caracteres des Leptoneta, mais elle est completement 

 aveugle." The completely blind Hadites is said by Simon to be near Agelena, differing "princi- 

 palement par la proportion de ses pattes et la disposition de ses filieres dont les anterieurs sont 

 tres longues et formees de deux articles." 



For the same reason — i. e., the lack of eyes and the great length of the limbs — the generic 

 term Phalangodes should at least be retained for P. armatus of Mammoth Cave. 



Coming to the Crustacea, there are the two generic names Caecidotsea and Orconectes. The 

 former name we applied to the cave and well-inhabiting G. stygia. The name is an unfortunate 

 one, having been originally applied to an imperfect specimen without caudal stylets; it bore con- 

 siderable resemblance to Idotsea, and I did not at first, from lack of specimens of Asellus, com- 

 pare it with that genus. Csecasellus would be a much more significant name. This genus has 

 been usually received by American naturalists who have had occasion to refer to it, but Prof. S. 

 A. Forbes, who has done excellent work on the species of this genus, refers G. stygia to Asellus. 

 Besides the lack of eyes, the body is much elongated, and the limbs, especially the antennse, are 

 very long; putting all these features together I think it is a great convenience to designate the 

 C. stygia and C. nickajackensis as generically different from the eyed species of Asellus, in which 

 the body is much broader and the limbs shorter. Against this view it may be said that some 

 individuals of Cceeidotcea stygia have rudimentary eyes. Moreover the genus Csecidotaea has not 

 been adopted by German and Swiss zoologists in referring to the eyeless Asellus forelii Blanc or 

 Asellus sieboldii De Rougemout. But in the case of these species the body scarcely differs in 

 shape from the common European Asellus aquations, the species apparently differing in their want 

 of eyes, smaller size, and white color. Until carcinologists unitedly insist that CsecidotEea is neither 

 a well-founded genus or subgenus we think it will not be objectionable to retain the use of the term. 



The second case is that of the genus Orconectes including what are generally known as Gamba- 

 r us pellucidus and G. hamulatus. The generic term was first proposed by Professor Cope for C. pellu- 

 cidus, and the second species, C. hamulatus, from Nickajack Cave, was also referred to that genus 

 by him. Objection has been made to the use of the term Orconectes by Dr. Hagen, also by 

 myself iu 1873, before two additional blind species had been discovered. In his valuable "Mono- 

 graph of the North American Astacidse," published before the genus Orconectes was proposed, 

 Hagen writes: "The most aberrant species [of Croup I, type acutus] is G. pellucidus. Like the 

 other animals living in caves, it is blind. * * * Nevertheless, the number of the hooked legs, 

 the form of the abdominal legs, and the elongated body and hands exclude C. pellucidus from the 

 other groups" of the genus. " Some, no doubt, will prefer to regard G. pellucidus as a distinct 

 group or genus, still, as I am convinced, without foundation." 



In his admirable Revision of the Astacidse Prof. W. Faxon does not admit the validity of 

 Orconectes, and states that 0. hamulatus "resembles G. pellucidus superficially, but belongs to 

 Group III, with hooks only on the third pair of legs in the male. The first pair of abdominal 

 appendages are very different from those of G. pellucidus, being formed after the pattern of those 

 organs in G. bartonii. The annulus ventralis of the female is also different" (p. 43). 



* Voyez Putzeys, Trechorum oculatorum monographia (Stettin, ent. Zeit., 1870, p. 9); et Abeille de Perrin, 

 Etudes surles Coleopteres cavernicoles, 1872, pp. 9-12. 



