COLEOPTEllA. 483 



spects the form of the joints of the tarsi and of their hooks, and 

 of that of the antennae and palpi, we find no common and con- 

 stant character. These Insects, however, are easily distin- 

 guished from other Heteromera of the same family, by the 

 general conformation of their body which is elevated and 

 arcuated ; the head is low, the thorax trapezoidal or semicir- 

 cular, and the elytra are very short or narrowed, and termi- 

 nate in a point, like the abdomen. Several of these Insects 

 approach the Pyrochroides in their antennae ; others, by their 

 maxillie, the hooks of their tarsi and parasitical habits, ap- 

 proximate to Nemognathus and Sitaris, subgenera of the last 

 tribe of this family ; but they are removed both from the for- 

 mer and the latter, by their extreme agility and the firm and 

 solid nature of their teguments. 

 They form the genus 



MorOella, Lin. 



In some, the palpi are almost of equal thickness throughout. 

 The antenna; of the males are strongly pectinated, or flabelliform. 

 The extremity of the mandibles is unemarginated. The joints of 

 the tarsi are always entire, and the hooks of the last one are den- 

 tated or bifid. The middle of the posterior margin of the thorax is 

 always strongly prolonged backwards, and simulates a scutelluni. 

 The eyes are not emarginated. The larvae of some of these Insects 

 — Ripiphori — inhabit the nests of certain Wasps. 



RiPiPHORus, Bosc. Fab. 



Their wings are extended, reaching beyond the elytra, which are 

 the length of the abdomen; the hooks of the tarsi are bifid; the an- 

 tennae, inserted near the inner edge of the eyes, are pectinated on 

 both sides in the males, serrated, or with but a single range of short 

 teeth in the females. The terminal lobe of the maxillae is very long, 

 linear, and salient, and the ligula equally elongated and strongly 

 bifid. 



Certain naturalists have found several living specimens of the 

 Ripiphorus paradoxus in the nests of the Common Wasp, which led 

 to the opinion, that they had lived there in their larvae state. Ac- 

 cording to an observation of M. Fariues, however, communicated to 

 Count Dejean — Ann. des Sc. Nat., VIII, 244 — the larva of the R. 



