480 COLYDIID. 
Subfam. DERETAPHRINA. 
Front coxe slightly prominent, separated only by a narrow band, which is not so 
prominent as the tips of the coxe. Hind coxe moderately widely separated. 
With this group we commence the series in which the basal joint of the antenne is 
quite exposed at the front of the head (Tab. XV. fig. 13a) when these organs are 
retracted ; the articulation between the first and second joints also is very peculiar. 
This latter feature is also found in the Bothriderine ; but the prosternal structure 
seems to separate the two divisions satisfactorily. 
SOSYLUS. 
Sosylus, Krichson, Naturg. Ins. Deutschl. iii. p. 288 (1845); Horn, Proc. Am. Phil. Soe. xvii. 
p. 581. 
This genus includes about twelve species; it is doubtful whether Metopiestes, Pascoe, 
can be satisfactorily distinguished from it. 
1. Sosylus terminalis, sp. n. (Tab. XV. figg. 12; 12a, extremity of the 
elytra. ) | 
Niger, opacus, minus elongatus, antennis pedibusque piceis; prothorace minus elongato, crebrius punctato, 
punctis anguste ovalibus ; elytris costatis, costa prima ante apicem alte elevata, apice libero, intervallis 
densissime subtiliter strigoso-punctatis. 
Long. 43 millim. 
Hab. GuaTEMALA, Zapote (Champion); Nicaracua, Chontales (Janson); Panama, 
Bugaba (Champion). 
The form of the head differs in the two sexes: in each of them it is flat, and has the 
epistome emarginate, but in the male this peculiarity is much more marked, and there 
is an elongate channel reaching nearly to the vertex, whereas in the female only the 
clypeus is so marked; in the male, too, the surface is nearly smooth except near the 
eyes, whereas in the female it is finely punctate. The thorax has the disc very convex. 
The first costa of the elytra is very strongly elevated behind, and has just before the 
apex a free, projecting extremity ; the second costa at the same level joins with the 
third, and the two are continued in a common sharply marked elevation quite to the 
tip; the intervals are very broad and have no trace of punctuation, but are rendered 
quite dull by a fine strigose sculpture. The under surface of the head and prosternum 
of the male are remarkable: the prominent smooth face of the projecting gena is twice 
as large as it is in the female; the prosternum just in front of the coxe is prominent, 
and the prominence is greater in the male and forms a transverse sharply marked 
line. oe . 
A South-American insect determined by the late Mr. Pascoe as being the Colydium 
rufipes, of Fabricius, is probably not specifically distinct from Sosylus terminalis. It 
