KEPORT ON THE ISOPODA. 15 



to be applied to Bovallius's Ianthe speciosa, it is clear that Ianthe bovallii cannot be 

 safely referred to any existing genus. I therefore propose to term this genus — 



Ianthopsis, n. gen. 



Body elongate and having the same general shape as in Jsera or Janira. Head 

 prolonged anteriorly into a short rostrum. Lateral regions of head as of thoracic segments 

 prolonged into processes; those of the head and the first segment of the thorax, as well 

 as of the three terminal segments of the thorax, are simple; in the second, third, and fourth 

 segments of the thorax the processes are bifid. Abdominal segments fused with deeply 

 serrate margins. Antennules with a very short flagellum, consisting of four or five joints; 

 antennae three times the length of antennules, with a long flagellum equal in length to the 

 two terminal joints of the peduncle; third joint of the peduncle with a spine which 

 represents the rudimentary exopodite (?). Mandibles furnished with a palp. Thoracic 

 appendages all similar to each other in both sexes, biunguiculate uropoda with a long 

 basal joint and two short rami, the inner longer than the outer. 



I have already indicated the differences between this genus and Janira, from which it 

 is sufficiently distinguished; it is also allied to Sars genus Acanthoniscus, from which, 

 however, it differs by the presence of eyes, by the rudimentary flagellum of the antennules, 

 and by the biunguiculate thoracic appendages (PI. V. fig. 5). 



Iolanthe, F. E. Beddard. 

 Iolanthe, F. E. Beddard, Proc. Zool. Soc. Lond., 1886, pt. i. p. 104. 



A large Isopod, dredged to the south of Kerguelen in 1675 fathoms, I regard as the 

 type of a new genus. It may be defined as follows : — 



Definition. — Head as wide as the first thoracic segment, terminating in front in a 

 long upturned spiny rostrum ; eyes absent. Lateral margins of head and of thoracic 

 segments prolonged into long curved spiny processes, which are single in the first and 

 last three segments of the thorax, but supplemented by an additional postero-lateral 

 shorter process in the head and in the middle segments of the thorax. Thoracic segments 

 with a single long median dorsal spine. Abdominal segments fused into a rounded shield 

 with three pairs of shorter lateral spines. Antennules half the length of antennae, with a 

 long multiarticulate flagellum ; antennae with an articulated spine on the third joint re- 

 presenting the exopodite ; (?) mandibles with a palp. Thoracic appendages (in female at 

 least) all similar to each other, biunguiculate. Uropoda as long as the abdominal shield, 

 with an elongate curved basal joint and two extremely short rami, of which the inner is 

 the larger. 



