DESCRIPTION OF A NEW SPECIES OF ISOPOD BELONGING 

 TO TIIE GENUS APSEUDES FROM ECUADOR. 



By Harriet Richardson, 



Collaborator, Division of Marine Invertebrates, United States National Museum. 



A single imperfect specimen representing a new species of Apseudes 

 was coDected off Cape San Lorenzo, Ecuador, by the U. S, Bureau of 

 Fisheries steamer Albatross in 1888. Although the anterior half of 

 the specimen is missmg, the part obtnmed is in such 

 good condition and so entirely distinct from any known 

 species that it seems worth while to describe it. 



APSEUDES MERIDIONALIS, new species. 



The single specimen is incomplete, consisting of only 

 the posterior half of the body — or the last three seg- 

 ments of the thorax and the abdomen. It measures 

 16 mm. in length and 3 in width. Each of the thoracic 

 segments is provided with four spmes on either side, 

 the two anterior being larger and longer than the two 

 posterior. Between the two posterior spines is situated 

 the epimeron, which is provided with two spines, one 

 at the antero-lateral angle and the other at the post- 

 lateral angle. The fifth and sixth thoracic segments 

 (fourth and fifth free segments) measure each 3 mm.; 

 the seventh segment (sixth free segment) measures 

 2^ mm. in length. 



The five anterior segments of the abdomen are sub- 

 equal and are each 1 mm. long; the lateral parts are 

 produced on either side in a process which is provided 

 with two small spines, one at the post-lateral angle 

 and the other halfway between that and the posterior 

 margin of the segment; the fourth and fifth segments 

 have additional smaller spines on the posterior margin of 

 these lateral processes. On the posterior margin of the 

 second, tldrd, fourth, and fifth segments are two small spines, one on 

 either side of the median line. The sixth or terminal segment is 4 mm 

 long; at the place of attachment of the uropods it is H mm. wide; at 



A.PSEUDES MERID- 



lONAUs. Pos- 

 terior HALF OI 

 BODY. X4}. 



Proceedings U. S. National Museum, Vol. 42— No. 1918. 



583 



