AMERICAN COLEOPTERA. 275 



the extrusion of the sexual organs and for the anal opening. This 

 cylindrical form is more or less modified in accordance with the 

 convexity of the abdomen ; in a robust species like Carp. paUipennis 

 the cylindrical form is quite perfect, while in Brachypeplus and 

 Colastus it is very much flattened. A very good idea may be 

 obtained of the structure of this segment, by examining the termi- 

 nal segment of the cylindrical larvae of certain Elateridte, such as 

 Agriotes or Elater. 



The genera in our fauna are four in number and have represetatives 

 on both sides of the continent, excepting Brachi/peplus. They are 

 distinguished as follows : 



Ventral segments 2—3 short, first, fourth and fifth longer CAEPOPHILTIS. 



"Ventral segments 1 — 4 short, fifth as long as the others united COLASTUS. 



Ventral segments 1 — 2 short, 3 — 4 longer, fifth still longer. 



Body depressed ; fifth ventral elongate but not conical BRACHYPEPLTJS. 



Body elongate, fifth ventral long and conical CONOTELUS. 



CARPOPHIL,IJS Steph. 



Labrum bilobed. Antennae eleven-jointed, terminated by a flat- 

 tened-oval, three-jointed club, grooves moderately deep, convergent. 

 Legs moderately robust, tibiae slightly broader at tip, spurs moderate. 

 Tarsi dilated, claws simple. Two sometimes three dorsal segments 

 visible beyond the elytra, abdomen beneath with segments 2 — 3 

 short, 1 — 4 — 5 longer. 



This genus is closely related to Colastus, but differs in the structure 

 of the abdomen and the sexual characters. Here must be placed 

 Tribraches Lee, the apparent equality in length between the first 

 three segments results from the extension of the abdomen in the 

 specimens on which it was founded. 



The males have an additional segment beyond the pygidium, which 

 is strongly deflexed and apparently belonging to the ventral series, 

 an illusion which is further heightened by an emargination of the 

 fifth ventral in which the sexual segment closely fits. That it belongs 

 to the dorsal and not to the ventral series is easily proven by dissec- 

 tion, or by the position of the anal opening when the segments are 

 extended. 



Several species have the middle tibiae stouter in the male, this is 

 especially noticeable in pallipennis. 



C. antiquus Er., is remarkable in having the posterior tibiae sud- 

 denly dilated in its apical half, as in the male Epmrse.a luteola Er. 

 This was noticed by Murray who failed to recognize its sexual 

 nature. 



