Relationships existing amongst Natural Objects. 415 
tirely concealed within the femora) it is allied to the Byrrhide ; but the 
leading character afforded by the maxilla evinces a near affinity with the 
Entomophaga, amongst which the Gyrinide must be considered the near- 
est in proximity, Gyrinus bicolor, Fab. somewhat approaching this 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 affinity, since, notwithstanding its Gyrinoid habit, 
clavate antennae, and subretractile legs, I have now ascertained that it un- 
questionably belongs to the Carabide, 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 tibize, simple tarsi, &c.* 
I should probably have long remained in ignorance of this most unexpected 
affinity, had it not been for the examination of another curious beetle, also 
from New Holland, which I purchased from a dealer, and which, having its 
legs and antenne retracted, I for a length of time regarded as a Gyrinus ; 
_ * 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. 
| ApzLoroPus Ipsorpes. W. Tas. XXVIII. fig. 2. | 
A. rufescenti-piceus; elytris paullo dilutioribus tenuissimè punctatis, genubus subtàs valde dilatatis, 
humerisque elytrorum sublevibus. 
Long. corp. lin. 34. Lat. lin. 14. 
Habitat in Australasia, (Adelaide.) A. H. Davis. 
Oblongus, convexus ; capite tenuissimé punctato, transverso, genubus subtüs maximis, et (capite supra 
viso) valdé prominentibus : antenne breves compresse, in canali profundo ad basim recepte. Palpi 
et antenne breves, piceo-rufescentes ; thorax lateribus subrotundatis, angulis posticis acutis ; margi- 
natus; lateribusque antice paullo recurvis, margine antico punctis minutis valde approximatis, po- 
sticé magis distantibus. Elytra tenue marginata, (versus humeros sublevia,) tenuissimè et irregu- 
laritér punctata. Pedes picei, femoribus maximis. Corpus subtüs pallidius, rufescenti- aut luteo- 
piceum, glabrum, nitidum. 
I have never met with any Coleopterous insect which exhibited so great a development of the genx 
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 antennæ. 
