NO. 2253. DESCRIPTIONS OF TEN NEW ISOPODS— BOONE. 595 



the smaller, outer branch is very narrow, obtusely pointed posteriorly, 

 and bears six teeth in the outer margin. The terminal segment and 

 both blades of the uropoda are heavily fringed with fine, closely set 

 hairs. 



Pleopoda : Four pairs, subequal, similar in structure ; the outer 

 branch is the larger and is broadly evenly rounded ; the inner branch 

 is about two-thirds the size of the outer and of similar shape. 



The holotype and an additional specimen (Cat. No. 50402, 

 U.S.N.M.) were collected in the Rio Berbice, British Guiana, by the 

 Rev. James Aiken, February, 1913. 



This species is at once recognized by the simplicity of the sculpture 

 of the telson. 



Family CYMOTHOIDAE. 



BRAGA OCCIDENTALIS. new species. 



Plate 91, fig. 1. 



Female. — Body ovate, 17 mm. long, 11 mm. wide. Head triangu- 

 late with the apex produced and slightly truncate, forming a blunt 

 rostral process about 1 mm. long. Eyes large, complex, elongate- 

 ovate, and located in the extreme postlateral angles of the head. 

 The first antennae are composed of seven short, stout, subequal 

 articles and are about three-fourths as long as the second pair. The 

 second antennae consist of eight short, stout, subequal, articles and 

 extend almost to the first thoracic segment. 



The first thoracic segment is 3 mm. long and has the anterolateral 

 margins slightly produced and the postlateral margins obliquely 

 truncated; the second and third segments are each 1.5 mm. long, 

 the fourth is 2 mm. long, the fifth and sixth are each 1.2 mm. long, 

 and the seventh is 0.9 mm. long. 



All of the segments except the first have the lateral area divided 

 by a diagonal carination, which causes the postlateral angles to appear 

 as elevated, horn-like projections; these segments have distinct epi- 

 mera extending along the lateral borders ; the epimera gradually in- 

 crease posteriorly in breadth and have the external postlateral angles 

 roundedly produced. All seven pairs of legs are strongly prehensile 

 and have the dactyl extremely curA'ed, the tip being excavated, some- 

 what resembling an arrowhead. 



The marsupial pouch is composed of three pairs of plates. These 

 are thoracically attached and are very convex, overlapping each 

 other like rosebud petals. 



Abdomen: This has the first segment entirely and the second 

 partly concealed by the seventh thoracic segment, the second seg- 

 ment appears about 1 mm. long and has the lateral parts concealed, 

 the third and fourth segments are each about 1.1 mm. long, the fifth 



