﻿242 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 102 



Description of holotype. — Specimen much broken. Approximate 

 length, 51 mm. ; gi'eatest width, 6.9 mm. 



Head entirely smooth, glabrous except for a few fine hairs near 

 labral margin. Clypeal furrow very distinct. A prominent trans- 

 verse ovoid swelling directly below each antennal socket. Antennae 

 rather stout, short, reaching back to anterior margin of third tergite ; 

 articles 2-6 of nearly equal size. 



Collum perfectly smooth, with a fine but distinct margining ridge 

 except on caudal edge. Anterior edge nearly straight, caudal edge 

 bent forward laterally. Lateral ends slightly truncate and marginal 

 ridges more prominent than across back. Second tergite wider than 

 collum and third tergite, its keels pronouncedly swept forward. 



Tergites completely smooth, except for extremely faint suggestions 

 of polygonal areas on the keels, to be seen when the dorsum is dry. 

 Keels of moderate width and length, never overlapping, set above 

 middle of body and nearly horizontal, thus interrupting slope of 

 the rather convex dorsum; anterior corners rounded off, posterior 

 corners produced caudad into a point on all keels back of third seg- 

 ment. Both anterior and posterior edges are set off by a marginal 

 ridge. Lateral edges inflated and smooth but for a slight notch on 

 the anterior shoulder. On poriferous keels the pores are lateral in a 

 large swelling. On the 19th segment pores are definitely inferior on 

 the small, distally rounded keel. Last tergite broadly truncate, 

 nearly tongue shaped, lateral edges almost parallel. A small median 

 terminal lobe. 



Anal valves smooth, with well-defined median ridges. Preanal 

 sternite nearly semicircular without lateral setiferous tubercules. 

 Last pair of legs separated by a distance equal to diameter of their 

 coxae; penultimate pair slightly farther apart. Bases of all legs fused 

 into a raised area very distinct from and higher than the prosternites. 

 Legs long and slender, end of third joint visible past keels in dorsal 

 aspect. Lengths of joints of legs, in order of decreasing length, 3, 

 6, 5, 2, 4, 1. Terminal claw slender and nearly straight. No special 

 processes associated with any of the legs. 



Sides and underparts all smooth and glabrous. A deep constric- 

 tion between prozonite and metazonite. In going toward the head, 

 the sternites tend to develop a small conical tubercle at base of each 

 leg. 



Gonopod aperture of medium size, oval, with caudal and lateral 

 raised edges. Pregenital legs unmodified. Seminal apertures small, 

 in end of coxae of second pair of legs, no special processes for them. 



Gonopods : Coxa short with a long slender trachial process and a 

 small hook just above exsertion of solenite. Pre femur and femur fused 

 into a straight, heavy, upright trunk, somewhat concave on one side 

 and densely setose; the opposite side is traversed by the seminal 



