372 DE. W. T. CALMAX ON NEW OE EARE 



to two-thirds of the length of the telson, its distal diameter about one-third of its 

 length. The exopod is about as long as the peduncle ; it has two unequal stout setae 

 at the tip and a single small seta on the inner and two on the outer edge. The 

 endopod is a little longer than the exopod and is unsegmented ; it has a long terminal 

 spine and six spines on the inner edge, the distal one much longer than the others ; 

 there are two or three seta? on the outer edge. 



Adult (t.) Male.— Total length 2-4 mm. 



The male differs from the adult female in having a much shorter distance between 

 the second and third pairs of legs, although the interval is more marked than in the 

 male of G. carincda. 



The carapace is shaped as in the female, with the pseudorostrum a little shorter 

 and broader, and with the antero-lateral angle rounded. The ocular lobe is a little 

 less prominent on the dorsal surface. The second leg-bearing somite is little longer 

 than the first and its pleural plate is produced forwards as a narrow lobe. The 

 pleural plate of the third somite is produced as a much broader lobe anteriorly. 



The last abdominal somite is but little longer than broad and less than half as 

 long again as the telson. The antennules have four segments in the outer flagellum. 

 As in the male of G. carincda, the third maxilliped has a well-formed exopod. The 

 difference in length of the rami of the uropods is a little more marked than in the 

 female and the endopod has only four spines on the inner edge. 



Eemarks. — The difference in size between the sexes, much greater than in the case 

 of G. cariiiata, throws doubt on the maturity of the male specimens described. In 

 the characters of the antenna, however, they seem to be adult, the peduncle having 

 a thick brush of seti3e anteriorly, and the short flagellum (which was unfortunately 

 broken in the specimen dissected) being distinctly segmented. 



This species, while agreeing with G. carinata in having no exopods on the third 

 and fourth legs of the male, differs from it in many important characters. Most 

 conspicuous among these is the great size of the second free thoracic somite in the 

 female. The first leg also differs greatly in the elongation of the basis and the feeble 

 development of setae on the propodus. Finally, the unsegmented endopodite of the 

 uropods distinguishes the species from all the other members of the genus. 



Occurrence. — "Lyttleton Harbour, 1-5 fathoms, 8/97, H. Suter Coll." Copenhagen 

 Museum. Co-types in British Museum. 



Gtnodiastylis costata, sp. n. (Plate XXXVl. figs. 1-10.) 



Description of adult Female. — Total length 2"3ri mm. 



Carapace about one-third of total length, its vertical height a little more than half 

 its length ; dorsal outline very slightly arched as seen from the side. Pseudorostrum 

 straight, horizontal, acutely pointed, a little less than one-fourth of total length of 

 carapace. Antennal notch widely open, defined below by the slightly produced 



