90 GEO. H. HORN, M. D. 



the structure of the antennas of the male, in which the joints 3 — 10 

 are furnished with an articulated appendage as long as the joint or 

 even longer, inserted near the base. 



PTIIiODACTYIiA Latr. 

 Head deflexed, clypeus distinct from the front and apparently 

 articulated. Eyes round, moderately prominent, partly concealed by 

 the angles of the thorax. Antennae arising very close to the margin 

 of the front, nearly as long as the body, slender, simple in the female, 

 in male with joints 4 — 10 furnished with an articulated appendage 

 arising from the base and as long as the joint itself. Labrum moder- 

 ately prominent, transverse. Mentum transverse, rounded in front, 

 ligula large, bilobed, the palpi short, the terminal joint oval. Maxillary 

 palpi longer, the terminal joint slightly triangular in the male, oval 

 in the female. Prosternum moderate before the coxae and very 

 narrowly prolonged between them, the coxae oval, prominent, without 

 trochantin. Middle coxae narrowly separated. Posterior coxae gradu- 

 ally but feebly dilated within and contiguous at middle. Abdomen 

 of five segments, the fifth longer and emarginate in the male. Legs 

 slender, with distinct terminal spurs, those of the posterior tibiae 

 longer. Tarsi with the first joint long especially on the hind legs, 

 the second and third are feebly bilobed and beneath the second is 

 slightly prolonged, the third has a long lobe, fourth joint small, 

 scarcely visible, fifth moderately long. Claws with a broad rect- 

 angular tooth at base. 



The form of the species is oblong, the head concealed from above 

 and the aspect much like some of the genera of the preceding sub- 

 family. 



Two species are known to me. 



Tooth of tarsal claw basal, not attaining the middle of the claw. 



Last segment of % emarginate, of 9 entire serricollis. 



Tooth of tarsal claw attaining the middle and on the anterior tarsi nearly as 

 long as the claw. 



Last segment % and 9 emarginate angustata. 



P. serricollis Say. — Oblong oval,castaneous or piceous, moderately shin- 

 ing, sparsely pubescent. Head coarsely and moderately densely punctured. 

 Thorax when viewed from above nearly semicircular, apex slightly prolonged 

 over the head, lateral margin acute, base feebly bisinuate, the margin finely 

 tridenticulate opposite the scutellum, disc convex, coarsely and moderately 

 densely punctured. Scutellum cordiform. Elytra oblong oval, not wider than 

 the thorax, sides moderately arcuate, disc moderately convex and with strise 

 of moderately coarse punctures, the intervals sparsely punctulate, scutellar 

 stria long. Metasternum shining, sparsely coarsely punctate. Abdomen sub- 



