CEIJSTACEA OF NEW ZEALAND. 211 



Jackson, probably Paranthura austrcdls, Ha.svvell, which lias only six pairs of legs, the 

 seventh segment of the pera^on being small and without appendages, as in Cruregens ; 

 my specimen is, however, only 3"5 millim. long, and is evidently immature. 



Cruregens fontanus, Chilton. (PI. XIX. figs. 1-22.) 



Cruregens fontanus, Chilton, New Zealand Journal of Science, vol. i. p. 44 (January 188.2) ; id. 

 Transactions New Zealand Institute, vol. .\iv. p. 175, pi. x. figs. 1-12; id. ibid. vol. xv. p. 88; 

 Humbert, Archives des Sciences physiques et naturelles, t. viii. p. 25G (September 1882) ; Chilton, 

 New Zealand Jom-nal of Science, ii. p. 89 (March 1884) ; Thomson & Chilton, Transactions New 

 Zealand Institute, vol. xviii. p. 152; Moniez, " Faune des Eaux souterraines du Departement du 

 Nord &c.," extrait dc la Revue Biologique du Nord de la France, tome i. (1888-89) p. 53. 



Specific diagnosin. No trace of eyes. Antennae subequal, upper slightly shorter than 

 the lower, and with four joints ; lower with the third joint only half as long as the fourth. 

 Pirst pair of legs with powerful subchelate hand; propodos triangular, broadest at base 

 palm straight, armed with two rows of setaj. Uropoda slender, inner branch narrow, 

 almost rod-like, not enclosing the end of the pleon. Telson linguiforin, extremity tipped 

 with three or four short setse. 



Colour translucent, slightly yellowish, owing to the liver-tubes showing through the 

 transparent integument. 



Length of largest specimens about 12 mm. 



Rabitut. Eyreton, North Canterbury {Chilton); Leeston {Ii. M. Luing) ; Winchester, 

 South Canterbury {JJ. L. Imoood) (in wells). 



Detailed Description. 



The following detailed description is derived from the comparison and examination 

 of a considerable number of specimens. I can detect no differences between the 

 specimens from the various localities mentioned above. 



Body (tig. 1). The body is cylindrical throughout; the head is slightly flattened 

 vertically and is smaller than the first segment of the peraeon. The first segment of the 

 perseon is rather shorter than the second and is rather loosely articulated to it, the body 

 being narrowed at this point, thus allowing free movement between the two ; the second 

 segment is in the same way loosely articulated to the third, though not quite to the 

 same extent ; the third, fourth, fifth, and sixth segments subequal, about as long as the 

 second, oblong in outline as seen in dorsal view, about half as long again as broad, 

 and firmly articulated together, the body not being narrowed at the articulations ; 

 the seventh segment is small, only about one-third as long as the sixth, and bears no 

 appendages. 



Pleon (tig. 20). The pleon to the end of the telson is rather longer than the sixth 

 and seventh segments of the perseon. The first segment is longer than the succeedino', 

 the second, third, and fourth are subequal, the fifth longer than the first ; each of these 

 five segments quite separate and bearing a seta on each side ; the sixth segment is 



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