DESCRIPTIONS OF A NEW GENUS AND SPECIES OF JAN- 

 IB1DM FROM THE NORTHWEST PACIFIC. 



By Harriet Richardson, 



Collaborator, Division of Marine Invertebrates, U. S. National Museum. 



In the material collected by the U. S. Bureau of Fisheries steamer 

 Albatross in the Northwest Pacific in 1906 there was a single 

 specimen representing a new genus and species of Janiridas. This 

 specimen has only recently turned up, so was not included in my 

 earlier report 1 on the isopoda of that collection. 



J^ERELLA, new genus. 



Head produced in the middle of the front in an extremely long 

 rostrum. Antero-lateral angles also produced in an extremely long 

 process on either side. Lateral margins of head produced on either 

 side in an elongate process. Eyes large, conspicuous and situated 

 some distance from the lateral margin. 



First segment of the thorax produced on either side in a single long 

 triangular process, similar to the lateral process of the head. The 

 following six segments have the lateral margins produced on either 

 side in two narrow elongate processes, equal in length to the lateral 

 process of the first segment. 



Abdomen consisting of a single large segment, the posterior margin 

 of which is produced in two long processes, posteriorly directed, and 

 the lateral margins of which are furnished on either side with a single 

 long triangular process. Uropoda, with a short peduncle and two 

 slightly unequal branches, are placed between the two posterior 

 processes of the abdomen. 



Head, first three and last three segments of the thorax ornamented 

 with two sharp spines, one on either side of the median line. Fourth 

 segment of thorax furnished with four spines, two on either side of 

 the median line, in longitudinal series. There is one spine on the 

 anterior portion of the abdomen in the median line. 



i Proc. U. S. Nat. Mus., vol. 37, 1909, pp. 75-129. 



Proceedings U. S. National Museum, Vol. 40— No. 1843. 



633 



