CRUSTACEA OF NEW ZEALAND. 185 



has not been so commonly obtained as the others ; this may perhaps be accounted for by 

 its habit of creeping instead of swimming like the Ampliipods. Moniez notes the same 

 thing with regard to Aselliis cavatictis, Schiodte, which is frequently found along with 

 Gammarus puteanus,'\i\\i\\ix,% not been met with from the district of Lille nor from 

 Prague, although the latter species is found at both places ; he accounts for this by 

 stating that, owing to the habits of the animal, it would rarely be brought up by the 

 pumps [78, p. 51]. 



The occurrence of Fhreatoicus typicus has been somewhat peculiar. Altliough the 

 Crustacea coming up the pump were pretty carefully watched and collected from January 

 1881, no specimen of Fhreatoicus was observed until the beginning of September 1882, 

 Avhile in a month from that date some six or seven other specimens, all females, were 

 obtained. I have not taken it again since then ; but in the year 1892 a single specimen, 

 also a female, was taken at Ashburton by Mr. Smith. This species is represented at 

 Winchester by a closely allied species, described in this paper as Fhreatoicus assimilis, 

 and of this I have three specimens only, two males and one female. 



From Leeston the following species are so far known — Gavimarus fragilis, Crangonrjx 

 comjjoctus, and Cruregetisf ontamis ; from Lincoln, Calliopius suhterraneus ; from Ash- 

 burton, Calliopins subterraneus, Gammarus fragilis, Cruregens fontanus, and Fhreatoicus 

 tgpiciis; from Winchester, Calliopins suhterraneus, Gammarus fragilis, Cruregens fon- 

 tanus, and the representative species Fhreatoicus assimilis. 



IV. Detailed Descriptions of the New Zealand Subterranean Crustacea. 



ISOFOBA. 

 Family PHREATOICID.E. 

 Genus Fhreatoicus, Chilton. 



(Transactions New Zealand Institute, vol. xv. p. 89.) 

 The following are the characters that I originally assigned to this genus in 1882, when 

 I had only one species, Fhreatoicus typicus, before me. They apply, with the sli"-ht 

 limitations given below, to the three species of the genus now known, and may therefore 

 still stand in the form in which they were originally put : — 



" Body long, subcylindrical, laterally compressed. Upper antenna short, lower Ion"", 

 with flagcllum. Mandible with an appendage. First pair of legs subchelate, others 

 simple ; first ybzw pairs articulated to body at the anterior ends of their segments and 

 directed forward ; last three articulated at posterior ends of their segments and directed 

 backward. Abdomen long, of six distinct segments, last joined to telson. Sixth pair 

 of pleopoda biramous, styliform. Telson large, subconical." 

 On this description I may make the following remarks : — 



1. The lateral compression of the body is not great and is seen chiefly in the pleon, 

 where the pleura of the segments are produced downward. 



2. "With regard to the legs, the first pair is subchelate in both .sexes, but is lar^'cr in 

 the male than in the female, and the fourth pair in the male is slightly modified so as to 



