216 DR. C. CHILTON ON THE SIJBTEEEANEAN 



(12) In CcMiopius svMerraneus there is very great dissimilarity between the two 

 sexes, cliiefly in the gnathopoda, both of these in the male differing considerably from 

 those of the female, while in other species one pair is usually almost or quite alike in 

 the two sexes. There are also differences in some of the mouth-parts, viz. in characters 

 which are often made use of for generic differentiation. 



Some remarks are made on the calceoli found in the males of this species ; they are 

 also found in some specimens which otherwise resemble the females, but these are looked 

 upon as immature males which have not yet acquired the peculiar gnathopoda of the 

 fully-developed male. 



V. The General Pauna of the Subterranean Waters of Canterbury. 



In addition to the Crustacea described in the present paper there are doubtless many 

 other forms to be found in the underground waters of the Canterbury Plains. In his 

 paper on the fauna of the subterranean waters of the North of France, Dr. R. Moniez 

 [78] gives a very long list, including Protozoa, Coelenterata, Turbellaria, Nematoda, 

 Annelida, Rotifera, Gasteropoda, and various Crustacea, in addition to the Amphipoda 

 and Isopoda, viz. Copepoda, Ostracoda, and Cladocera. In the various caves of North 

 America, as described by Packard [83], and likewise in those of Europe, described 

 by Joseph [67] and other writers, the fauna is a very extended one, and naturally 

 includes many air-breathing forms that would be unable to exist in subterranean 

 waters. 



I have made no extended search for other forms from the wells of Canterbury, but in 

 collecting the Crustacea I have occasionally met with others, and it will perhaps be well 

 to mention briefly here what is known on the subject, in the hope that greater attention 

 will be directed to the matter in the future. 



Attached to tlie Amphipoda {Crangonyx compactns, Gammarus fragilis, CalUop'ms 

 stiUerraneus) I have, on several occasions, noticed a small stalked Infusorian, probably 

 a Vorticella, or something allied thereto. Various worms have been lirought up by the 

 pump — one, an Oligochsete, is, Professor Haswell tells me, Phreoryctes Smiihii, Beddard ; 

 another is a very remarkable Turbellarian, which is at present being investigated by 

 Professor W. A. Haswell, of Sydney. 



Mr. W. W. Smith, who has examined the water brought up by pumps in the Ashburton 

 district with great care and jjerseverance, has succeeded in detecting several forms 

 that have not yet been observed from the Eyreton wells. Among these are some 

 small Gasteropoda, a small Centipede, and a jieculiar worm, Phreodrilus subterraneus, 

 Beddard [8]. The shells have been observed from several wells, but only very few 

 specimens have as yet been obtained ; these were submitted to Mr. Suter of Christchurch, 

 who states tliat they appear to be Potamopyrgus anti})odum, Gray, var. spelcBci, Prauenfeld. 

 P. antipodnm is a freshwater species which is very widely distriliuted in New Zealand, 

 and has probably received various names for its different varieties ; the type of P. spelcea 

 was found in the Collingwood Caves near Nelson. There seems no doubt that the shells 

 found at Ashburton really belong to the true subterranean fauna, as Mr. Suter states 



