1904.] NATURAL, SCIENCES OF PHILADELPHIA. 65 



Aplopus similis n. sp. 



Types. — c? (immature) and 9 ; Swan Island, Caribbean Sea. [Cat. 

 No. 7,343, U. S. N. M.] 



Closely allied to A. ligia Westwood,^''' but differing in the much 

 shorter antenna, longer mesonotum and posterior limbs, the different 

 character of the lateral expansions of the sixth abdominal segment, and 

 the decidedly shorter subgenital opercule. 



c?. — Size medium; form rather elongate. Head slightly longitudi- 

 nal; occiput with two large acute spines of Avhich the right is the larger, 

 posterior margin of the head with a pair of small median spines ; eyes 

 subglobose; antennae stout, somewhat depressed, slightly exceeding in 

 length the head, pronotum and mesonotum, basal joint oblong, strongly 

 depressed. Pronotum slightly longitudinal, anterior margin concave, 

 posterior margin convex, lateral margins with a very prominent and 

 deep semicircular emargination ; transverse sulci two in number, one 

 prominent and immediately posterior to the anterior margin, the other 

 submedian and shallower in character ; anterior half of the pronotum 

 with two pairs of spines, the anterior of which is more distinct than the 

 posterior, the remaining portion of the surface granulate. Mesonotum 

 equal to the three basal abdominal segments; anterior portion con- 

 stricted, gradually expanding to near the median portion, which is 

 equal to the posterior width ; surface with five pairs of irregularly placed 

 spines, two pairs being very close to the anterior margin, while more 

 than the posterior third of the whole surface is free from spines ; lateral 

 margins with an even row of low tubercles ; mesothoracic pleura w^ith 

 a number of subobsolete protuberances ; mesosternum with four pairs 

 of low evenly placed tubercles. Metanotum about two-thirds the length 

 of the mesonotum, median segment occupying very slightly more than 

 half the length; metasternum with a few very obsolete tubercles. 

 Tegmina and wings not developed, the rudiments very small. Abdo- 

 men considerably exceeding the head and thoracic segments in length: 

 five basal segments longitudinal, simple, the fourth and fifth slightly 

 shorter than the first to third; sixth segment longitudinal, slightly- 

 shorter than the fifth in length, the posterior lateral portions developed 

 into smaller triangular lobes; seventh segment slightly shorter than 

 the sixth; eighth and ninth segments smaller than the preceding seg- 

 ments, equal in length, both carinate, apical portion of the ninth 

 truncate and with a distinct thickened elevated rim; cerci short, thick 

 and rounded, but slightly exceeding the apex of the ninth segment; 

 subgenital opercule large, slightly exceeding the eighth dorsal segment 



20 Catul. Orth. Ins. Brit. Mus., I, p. 89, PI. XI, figs. 1 and 2. 



