22 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.60. 



ond tergite as in nicaraguanus, or nearly so. Sulcus obscure in mid- 

 dorsal region. The tergites in general smooth, with striae only be- 

 neath. Sulcus complete, but not deep across dorsum. The scobina 

 with anterior impression widely and narrowly elliptic; the striate 

 area wider anteriorly than the elliptic impression, narrowing caudad. 

 Scobina present back to the fifth or sixth segment from caudal end, 

 but the most posterior ones lacking the anterior impression. Caudal 

 process of last tergite acute in general outline, but rounded at end. 

 The anal valve broadly subtrapeziform, but the caudal side very 

 obtusely angular, thus giving in reality five sides (see pi. 10, fig. 4). 



Gonopods as shown in plate 10, figures 5 and 6. 



Number of segments in male type, 45. 



Length, about 88 mm.; width at middle 11 mm., at penult segment 

 7 mm., anteriorly 9.5 mm. 



Locality. — Costa JKica, one male (Bergdorf and Schild), Ace. 38, 

 962. 



Type.— Q2it. No. 830, U.S.N.M. 



Resembles R. tristani Pocock, but differs in larger size, coloration, 

 form of telopodite of posterior gonopods, and in form of scobina. 



46. RHINOCRICUS SIMULANS, new species. 



Plate 10, figs. 7-10. 



Through long preservation with drying the type does does not 

 show the original coloration clearly. It seems, however, to have been 

 a shade of olive, with a caudal ferruginous border on each segment 

 narrower than that of centralis. Legs and antennae yellowish. Sen- 

 sory cones of antennae numerous. Ocelli in six transverse series in 

 each eye, about 32 in number. The collum of the usual general 

 form, smooth. Margining sulcus not extending at all up anterior 

 margin. Second tergite produced below, as in the preceding species. 

 The sulcus obscure dorsally. Sulcus on the following tergites com- 

 plete. Surface smooth, with the usual striation beneath. Scobina 

 formed nearly as in centralis (see pi. 10, fig. 8) ; present back to 

 eighth from last segment. The anal tergite extending over valves 

 above, or nearly so. The last sternite differing conspicuously from 

 those of the preceding two species in being strictly triangular, the 

 sides straight, or nearly so, and meeting in a slightly obtuse angle 

 behind (pi. 10, fig. 7). 



Gonopods as shown in plate 10, figures 9 and 10. 



Number of segments, 45. 



Length, about 85 mm. ; width, 10 mm. 



Locality.— Costs, Rica (C. Bergdorf and P. Schild), U.S.N.M. Ace 

 38,962. 



Type.— Cat. No. 831, U.S.N.M. 



