Relationships existing amongst Xatiiral Objects. 413 



tirely concealed within the femora) it is allied to the Bi/rrhidœ ; but the 

 leading character afforded by the inaxillœ evinces a near affinity with the 

 Entomophaga, amongst which the Gyrinidœ must be considered the near- 

 est in proximity, Gyrinus bicolor, Fab. somewhat approaching tliis insect in 

 form." 



Very ample details were figured of this most extraordinary insect, which 

 certainly presents one of the most interesting instances of analogical relations 

 which have hitherto been published. That such is the case, must be certainly 

 admitted, when the preceding observations upon its relations are considered 

 with reference to its actual atfinity, since, notwithstanding its Gyrinoid habit, 

 clavate antennœ, and subretractile legs, I have now ascertained that it un- 

 questionably belongs to the Carahidce, and that it is very closely allied to 

 Pseudomorpha, with which it agrees in the peculiar structure of the under- 

 side of the head, very short maxillary palpi, hatchet-shaped labial palpi, large 

 femora, slender tibise, simple tarsi, &c.* 



I should probably have long remained in ignorance of this most unexpected 

 affinity, had it not been for the examination of anotlier curious beetle, also 

 from New Holland, which I purchased from a dealer, and which, having its 

 legs and antennae retracted, I for a length of time regarded as a Gyrinus ; 



* I am indebted to Mr. Edward Newman, F.L.S.,for an opportunity of describing and figuring a 

 new species of the genus Adelotopus, of which the following are the characters. 



Adelotopus Ipsoides. W. T.\b. XXVIII. fig. 2. 



A. rufescenti-piceus ; elytris pauUo dilutioribus tenuissimè punctatis, geuul)us subtùs valdè dilatatis, 

 humerisque elytrorum sublsevibus. 

 Long. Corp. lin. 3|. Lat. lin. 1|. 

 Habitat in Australasia. (Adelaide.) A. H. Davis. 



Oblongus, convexus ; capite tenuissimè punctato, transverso, genubus subtùs maximis, et (capite supra 

 viso) valdè prominentibus : antennœ breves compress», in canali profundo ad basim recept», Pa/iji 

 et antenna breves, piceo-rufescentes ; thorax lateribus subrotundatis, angulis posticis acutis ; raaro-i- 

 natus ; lateribusque anticè paullè) recurvis, margine antico punctis minutis valdè approximatis, po- 

 sticè magis distantibus. Elytra tenue marginata, (versus humeros sublïevia,) tenuissimè et irregu- 

 laritèr punctata. Pedes picei, femoribus maximis. Corpus subtùs palhdius, rufescenti- aut luteo- 

 piceum, glabrum, nitidum. 



I have never met with any Coleopterous insect which exhibited so great a development of the gena- 

 on the underside of the head, here forming a large elevated plate on each side of the mouth between 

 the trophi and the base of the antennae. 



