CEUSTACEA OF NEW ZEALAND. 173 



S. A. Forbes [41] , in 1876, describes au Amphipod found in a well at Normal, Illinois, under 

 the name Crangonyx mucronatus. This species is, he says, perhaps entitled to rank as the type 

 of a new genus, but for want of material for a more general study of its relations it is left with its 

 nearest allies in the genus Crangonyx. The diflFerences between the sexes are given, the most 

 remarkable being in connection with the telson, which is very largely developed in the male. (See 

 below, pp. 218-219.) 



Alois Humbert [62] published his description of Niphargus puteanus, var. Forelii, in 1876. Besides 

 a very careful and minute description of this variety, and of another named onesiensis, this work contains 

 much important information on the general subject of blind subterranean Crustacea. After some 

 introductory remarks he gives an historical sketch of previous works on the subject, in the course of 

 which he fully criticizes de Rougemont's views as already stated, and pointed out tliat his own 

 observations do not at all correspond witli those of de Rougemont : thus among the specimens handed 

 to him by Professor Forel were some very small, only 2 millim. long, which should therefore correspond 

 with de Rougcmont's first form, and belong to Crangonyx subierraneus , Speuce Bate; but these, 

 Humbert says, already had the characters well marked, the two gnathopods already having the form of 

 the adult and the telson being deeply cleft. Humbert then considers the characters of the genus 

 Niphargus, and gives a new definition of it. He discusses the place in the genus of his own varieties, 

 and compares them with the species previously described by other authors. He distinguishes two 

 varieties, Niphargus puteanus var. Forelii, from the deep waters of the Lake of Geneva, and N. puteanus 

 var. onesiensis, from a well at Onex near Geneva, and gives at length the minute differences between 

 the two. In considering the origin of the Niphargus found in the Lake of Geneva, he gives good reasons 

 for believing that it is not merely a modification of Gammarus pulex, and concludes that it is probably 

 descended from an ancient genus now extinct ; he is inclined to think the Niphargi of the lakes come 

 from those in the subterranean waters. This point was afterwards fully considered by Professor Forel. 

 who finally came to the same conclusion as Humbert, though he had previously thought otherwise [40, 

 pp. 170-183]. 



In the detailed description of Niphargus puteanus, var. Forelii, that follows, Humbert pays special 

 attention to the various organs of sense. On the head and on the first segments of the pereion, on the 

 dorsal portion, arc found "capsules sensitives," and on the upper antenn;e " cyliudres olfaetifs,'' 

 " batonnets hyalins," " soies auditives," and also " capsules sensitives " like those on the head, &c. 

 The females are said to be distinguished from the males by their smaller size, the brood-plates, and the 

 shorter length of the terminal uropoda. 



P. GoDET [49], in 1878, was induced by Humbert^s criticism of de Rougemont's work to rectify his 

 measurements of the large specimen from Neuehatel, as his measurements previously given had not 

 corresponded with those given by de Rougemont. In connection herewith de Rougemont stated that he 

 still held to his opinions previously published. 



J. D. Catta [20], in 1878, described a new species of Ami)hipod, Gammarus rhipidiophorus, found only 

 in a well at La Ciotat (Bouchcs-du- Rhone, France), a hundred yards or so from the Mediterranean; the 

 water in the well becomes brackish in summer. He considers that the genus Niphargus %ho\x\A be given 

 up, as the various differences between them are more or less bridged over by different species. In 

 connection with this question, however, Wrzesniowski points out [I21, p. 607] that Catta says nothing 

 about the mouth-parts, in which arc found some of the most prominent marks of distinction; and 

 Stebbiug also says : — " The discovery of transition-forms between two genera will always cause some 

 difficulty, but as such forms have probably existed in innumerable cases where they have not been 

 discovered, it is a question how far the discovery of them should be allowed to interfere with well- 

 established distinctions cither of genera or species. 'When Niphargus aquilex and Gunmiarujs pulex are 

 side by side, it is rather the difference of the fades than the likeness which attracts attention" [108, 

 p. 475]. It may here be added, the differences originally laid down between Niphargus and Crangonyx 



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