178 DR. C. CHILTON ON THE SUBTEEEANEAN 



R. Schneider [96], 1855, described from the mines at Clausthal a variety of Gammarus pulex, under 

 the name G. pulex var. subterrantus, which diflers from the normal specimens of the species in its loss 

 of colour, the partial degeneration of the eyes, the possession of two joints only in the secondary 

 flagellum of the upper antennae as in Kiphargus puteanus, &c. Schneider appears to consider it to some 

 extent intermediate between Gammarus pulex and N>pha7-ffus puteanus. In connection with it Stebbing 

 says : " The special interest of the form lies in its occurrence in the waters of mines of which the age 

 can be more or less definitely ascertained'' [108, p. 573]. It is discussed by Moniez, who has found a 

 somewhat similar form at Emmenn [78, p. 39] . 



Karl BovALLius [15], in 1886, in his 'Notes on the Family Asellidai,' mentions and gives brief 

 descriptions of Asellus Forelii, Elauc, A. Sieboldii, de Rougemont {=A. cavaticus, Schiodte), and 

 Catcidotcea styyia, Packard. He omits Cacidotaa nickajachensis, Packard, the account of which he had 

 evidently not seen. In the introduction [15, p. 3] he says :— " Ccecidotcea seems to be closely con- 

 nected with Asellus Forelii and A. cavaticus, but without any knowledge of the form of its pleopoda it is 

 impossible to say whether it ought to be united with Asellus or not." 



R. Schneider [97], in 1887, described a new variety freibergensis, Schn., of Asellus aquaticus, found 

 in the water of the mines of Freiburg. It bears to A. aquaticus much the same relation as Gammarus 

 pulex var. subterraneus, Schn., does to the normal G. pulex. It is smaller, quite coloui-less, the eyes 

 persistent, but presenting the same example of degradation as in G. pulex var. subterraneus. 



A. E. JuRiNAC [68] found in the caves of Croatia a species which he first named Eriopis croatica 

 and aiterwards Ni^jhargus croaticus. According to Moniez, it is characterized by the antennae, which 

 are longer than the body, and contain 73 joints, the last six segments of the pleon are furnished with 

 a thick row of forked spines, the hand is almost square in the female and oval in the male [78, p. 49}. 



A. S. Packard-'s [83] paper on "The Cave Fauna of North America" was read in November 1886, 

 but I am unable to find out exactly when it was published. It contains a very full and comprehensive 

 account of the various caves, with the fauna of each, and a discussion on some of the points of general 

 importance presented thereby. The cave Isopoda given are Ccecidotcea stygia, Packard, and C. iiicka- 

 jackensis, Packard. A fuller account than had previously been published is given of tlie genus Ccecidotaa, 

 which is retained as distinct from Asellus " on taxonomic grounds " *, and, as it is pointed out, it preseuts 

 constant diflerences from the blind Isopods of European caves and wells and from the depths of 

 the Swiss lakes, which, though exposed to similar conditions, have developed in a different du'ection. 

 The two species C. stygia and C. nickajackensis are described in some detail and compared with the 

 surface species Asellus communis, and the author says : " It seems quite evident that the two species 

 have descended fi'om different species of Asellus. Whether there is an additional species in the 

 Southern States from which the present species [C. nickajackensis^ may have been derived remains to 

 be seen" [83, p. 33]. Two species, A. intermedius and A. brevicauda, described by Forbes from 

 Southern Illinois, are mentioned, but it is stated that neither has been found in central or northern 

 Illinois, "although the most varied situations were carefully searched" [83, p. 33]. The Amphipoda 

 given are Crangonyx vitreus, Smith {= Stygobromus vitreus, Cope), C. Packardii, Smith { — C. vitreus, 

 Packard), C. antennatus, Packard, C. mucronatus, Forbes, and C. lucifugus, Hay. Of the three last 

 mentioned, the original descriptions given by their authors are simply reproduced, the other two are 

 described and figvu-ed by Professor S. I. Smith. Of the first species, C. vitreus, he says : — " I know of 

 no species with which this is closely enough allied to make its affinities of any value on the question of 



* Since this was written I have, through the kindness of Mr. W. P. Hay, received specimens of Circidokra stygia 

 from wells in Irvington, Indiana , and they differ so much in the proportions of the body aud in other points from 

 Asellxis communis, of which Mr. Hay has also sent me specimeus, that I folly agree with Packard that CacidoUza 

 should rank as a distinct genus separate from Asellw. 



