250 Transactions.—-Zoolo gy. 
close together between the two external, completely exposed. Antenne 
hirsute towards the extremity; basal joint short; fifth joint expanding 
posteriorly; flagellum short and thick, all the joints together not so long as 
preceding. Colour brown. Whole body more or less covered with minute 
granules, 
In the female each segment of the body is furnished with a row of stout, 
obtuse spines, which are longest towards the side of the thorax. In the 
male the whole body is nearly smooth. Length :8 to 1:2 inch. 
Auckland Islands (Mr. Jennings). 
Art. XX.— Description of a New Species of Isopodous Crustacean (Idotea). 
By George M. Tuomson. 
( Read before the Otago Institute, 2Gth November, 1878.) 
Tar animals forming the genus /dotea are readily distinguished from other 
Isopods by having the segments of the abdomen more or less coalescent, 
and fewer than the normal number, seven, and particularly in having the 
“terminal segment very large, its appendages greatly developed, covering 
the whole inferior surface of the abdomen, and closing like doors over the 
branchial appendages.” 
Of the three species described in Miers’ Catalogue of N. Z. Crust., 
pp. 92, 93, the first, I. argentea, Dana, is a doubtful New Zealand species, 
having been obtained by Dana near New Zealand. It is found on the 
Australian Coasts, and also at Borneo, and is probably common in the West 
Pacific. The second species I. affinis, M. Edw., is common on our coasts, 
and seems to be the same as a species found on St. Paul's Island, and at the 
Cape. The third, I. elongata, Miers, has only been found hitherto at the 
Auckland Islands. The species which I now propose to add, is chiefly 
remarkable for its habitat, being the only species, as far as I can find out, 
occurring in fresh water. Numerous specimens were found by Prof, Hutton 
in the Tomahawk lagoon, near Dunedin. They were creeping about under 
stones, and appeared to be feeding on the ova of a fish, probably Galaxias, 
sp., which was found abundantly in the same locality. Whether they occur 
permanently in the fresh water, or only come up when a very high tide 
renders communication with the lagoon possible, I cannot say. The species 
is a distinct one, and has not hitherto been found on our coasts. 
