234 Transactions. — Zoology. 



Art. XI. — Descriptions of neiu Crustaceans. By Geo. M. Thomson, F.L.S. 



[Read before the Otago Institute, 31st October, 1882.] 



Plates XII and XIII. 



Fam. MGIDM. 



Sllb-fani. ClEOLANINiE. 



Genus Pseudsega, n. gen. 

 Eyes rather small. External antennae hardly separated from one another. 

 Inner antennas tolerably elongated. Legs all adapted for walking. 

 Epimeraa well-developed, and produced acutely backwards. Abdomen 

 distinctly 5-jointed ; last segment large. Caudal appendages reaching its 

 extremity. 



1. Pseud cega punctata, n. sp. PL xii., figs. 11-13. 



The body is somewhat oval in outline, concave above, and nearly flat on 

 the under-surface. The head is nearly square, and is inserted into the first 

 thoracic segment, which considerably exceeds the other subequal segments 

 in length. The abdominal segments are very distinct ; tbe 4th and 5th 

 are overlapped at the sides by the preceding segments. The last segment 

 is triangular, with somewhat rounded edges, which are fringed with long 

 hairs, and ends in a sharp point. The eyes are placed in the lower and 

 outer angles of the head, and are nearly hidden by an upward-toothed pro- 

 jection of the 2nd joint of the external antennas. These organs are very 

 close together at the base, and the point of their flagellum just reaches the 

 suture between the 4th and 5th thoracic segments. The internal antennas 

 are much more slender, but the peduncle reaches the extremity of the 

 peduncle of the outer pair, while the flagellum reaches to about the middle 

 of the 2nd thoracic segment. 



The legs increase in length posteriorly, the 7th pair being considerably 

 the longest. The caudal appendages reach the extremity of the abdomen, 

 and are fringed with long hairs ; the inner branch is very broad, and 

 has a long acute tooth on its outer margin ; the outer branch is nearly 

 linear. 



All the legs and the margins of the epimeraa are furnished with roughish 

 hairs, but the upper part of the body is smooth. The general colour is 

 grey, owing to the integument being covered with minute black stellate 

 markings. Length '5 inch. 



Loc Washed up on the Ocean Beach, near Dunedin. 



I advance this genus and species provisionally, as I cannot satisfactorily 

 place it in any of the existing genera. A revision of the Isopoda is very 

 much wanted. 



