108 Transactions. — Zoology. 



Hab. Common on seaweed along the shores of Otago Harbour, and in 

 rock pools, and dredged in the harbour in six fathoms ; also collected by 

 Mr. C. Chilton on seaweeds in Lyttelton Harbour. 



2. Porcellidium interrupttvm, n. sp. PL XI., fig. 15. 



Body very broadly oval, width nearly equal to three-fourths of the 

 length ; first segment about half as long as body ; last thoracic segment 

 produced behind into long pointed lamellae, which nearly meet posteriorly 

 in the median line behind the caudal segments, the outer margin of each is 

 finely ciliated and produced about the middle into a short spine. Inner 

 branch of the first feet triangular, very broad at the base ; outer branch 

 nearly as long as inner. The second pair of feet have the outer branch 

 short, hardly exceeding in length the first joint of the inner branch. Fifth 

 feet form two somewhat curved lamellfe, the inner of which almost extends 

 to the extremity of the caudal segments : these last are rather longer than 

 broad, their sides are nearly parallel, and their posterior margins fringed 

 with a few short teeth. Length, -^ of an inch. 



Hab. Two specimens (both females) taken by the dredge in Dunedin 

 Harbour. 



This is a very remarkable form and quite different from any hitherto 

 described. 



Sub-fam. Idytiwe. 

 Genus Idya, Philippi. 



Cephalothorax broad and somewhat depressed ; abdomen narrow, 5- 

 jointed. Head coalescent with first thoracic segment. Anterior antennas 

 7- or 8-jointed, elongated ; posterior 3-jointed, with a large 4-jointed 

 secondary branch. Mandible long and strongly toothed ; palp 2-branched, 

 basal joint short, branches 1 -jointed, long and slender, setiferous at the 

 apices. Maxilla armed with several slender terminal teeth ; palp well de- 

 veloped. First and second foot-jaws nearly alike, hooked; first pair 2-, 

 second 3-jointed. Inner branch of the first pair of feet 2-jointed, clawed ; 

 outer branch short, 3-jointed ; three following pairs with both branches 3- 

 jointed. Fifth pair elongated, 2-jointed. Ovisac single. 



1. Idyafurcata, Baird. PI. VIII. , figs. 1-8. 



(For synonymy of this species, see Brady's Mon. Brit. Cop., vol. ii., p. 172.) 



Body elongated, somewhat pyriform ; rostrum short and obtuse. An- 

 terior antennas 8-jointed, first four joints much stouter than last four ; their 

 comparative length is tabulated by Brady as follows : — 

 1, 2, 3, 4, 5, 6, 7, 8, 

 10. 18. 13. 18. 3. 3. 2. 8. 

 This character is said by Brady, Claus and others to vary considerably, but 

 the following taken from my own specimens shows almost the same relative 

 lengths except in the fourth joint, viz. : — 



1, 2, 3, 4, 5, 6, 7, 8, 

 12. 19. 15. 12. 4. 5. ~li. 9. 



