ISOPODA. 43 



follows : " Body very flexible and almost smooth in front, but granular and setose 

 in the hinder half. Front obtuse as in Sphceroma ; hind margin of the first pleon 

 segment furnished with two rounded tubercles ; two tubercles similar but much 

 larger, more salient and above all more elongated, situated on the last pleon segment 

 and separated by a longitudinal furrow, at the extremity of which is found a boss 

 furnished with a pencil of long setse. Terminal incision of the pleon very wide ; the 

 elongate median process almost cylindrical, rounded at the end, and terminating at 

 the level of the extremity of tbe two teeth formed by the sides of the incision. 

 Terminal plates of the uropods reaching much beyond the extremity of the pleon ; 

 the inner large and obtuse ; the outer much broader, thin on the inner side, but very 

 thick towards the outer margin and armed with a conical tooth at its extremity. 

 Length about 6 lines. Habitat, the Mediterranean." A length of 12'5 millims., 

 compared with 6 millims., makes the difference in size very considerable, but in other 

 respects there is a close resemblance between the Pacific species and that described 

 from the Mediterranean. 



Localities : East of Shoal buoy ; off Chilavaturai ; on trap sunk to bottom, Shoal buoy. 



Cymodoce inornata, Whitelegge. 



1902, Cymodoce inornata, Whitelegge, ' Mem. Australian Mus.,' iv., pt. 4, p. 263, fig. in text. 



The specimen referred to this species agrees well with Mr. Whitelegge's account 

 and figure. It has the body minutely hairy, the pigmented area of the eyes with 

 the narrow end directed backwards, the process in the apical sinus of the telsonic 

 segment small and rounded, the outer ramus of the uropods bidentate, with the outer 

 tooth smaller and higher up than the inner. 



On the other hand, it should be stated that the apical sinus is much more marked 

 than that which Mr. Whitelegge represents, and the tip of the median process 

 scarcely reaches the level of the apices of the sinus. The outer ramus of the uropods 

 is not so forcibly bidentate as in Mr. Whitelegge's figure, and above the semi- 

 circular depression, which that author mentions as extending from one uropod to the 

 other, the telsonic segment is here bilobed. In the Australian memoir it is spoken of 

 simply as convex. 



Length about 12 millims., equal to twice the breadth. The specimen was crowded 

 with young ones, in which the eyes were already visible. 



Locality : Coral reefs, Gulf of Manaar. A second specimen was taken south of 

 Adam's Bridge. 



Tribe: VALVIFERA. 



To the tribe, in 1897, Sars assigned the three families Idotheidse (synonymous 

 with Idoteidse), Arcturidse (with suggestion of AstacillidaB as the proper substitute), 

 and Chaetiliidse. The late Axel Ohlin in 1901 added a new family, Pseudidotheidse, 

 to receive the three species, Idothea miersii, Studer, Pseudidothea bonniem, Ohlin, 

 and Arcturides cornutus, Studer. He was, however, almost convinced that the first 



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