MR. A. MURRAY'S MONOGRAPH OF THE FAMILY OF NITIDULARLE. 223 
one of the species of that genus, Rh. depressus, has been described both by Erichson and 
Perris; but the descriptions of these two authors do not correspond; and Erichson's 
description must be cancelled or transferred to some other species, for he mentions that - 
he assumed it to be the larva of that species only from finding a number of them in com- 
pany with the perfect insect; while Perris, on the other hand, carefully and repeatedly 
bred the insect, and there seems no reason to doubt that perfect dependence may be placed 
on his observations. I also have received specimens of larvee supposed, on the same 
grounds as those relied on by Erichson, to belong to Rhizophagus depressus; but these 
differ both from Perris's and Erichson's descriptions, and of course are useless, and I only 
mention the circumstance to show the difficulty attending the study of the larvee of this 
family. Few can be bred; and unless this be done, we can have no assurance that the 
larva really does belong to the species to which it is referred. I have received specimens 
of larvee referred to different Nitidulide, which on examination turned out to be the 
larvee of Diptera; and I have others given me as belonging to particular species of 
Nitidula, but which I cannot use from want of sufficient evidence that they really do so. 
The result of this difficulty in determining the larve is that even yet there are not 
more than about half a dozen species described which can be relied upon— Carpophilus 
sexpunctatus by Perris, Soronia grisea by Curtis and Erichson, Meligethes eneus by 
Heeger, Lordites glabricula and Amphicrossus discolor by Candèze, and Ips ferruginea by 
Perris. 
Confined as we are therefore to such imperfect and doubtful materials, any attempt at 
generalizing is out of the question; all that we can say is that the following characters 
have been met with in the different species which have been described :— 
Head.—Small, depressed, rounded. 
Ocelli.—Placed behind the antennæ, varying in number from two to four on each side. 
Antenne.—Usually four-jointed; but Erichson says that in Soronia grisea they are 
only two-jointed ; and in another Nitidularian larva which I have received as Meligethes 
eneus they are only three-jointed. 
Labrum.—Short, transversal, and sometimes bilobed. 
Mandibles.—Lamellar ; usually dentate on the inner side and expanded at the base 
into a broad flat plate. 
Mazilla.—With one lobe only. None of the Brachypteride, however (which in the 
perfect state have two lobes), have yet been examined; but it is to be observed that in 
other Clavicorns which in the perfect state have two lobes to the maxillz (the Colydiude 
for example) there appears to be only one lobe in the larva. 1t is soldered to or con- 
tinuous with the mentum. 
Maxillary Palpi.—Three- or four-jointed. 
Ligula.—Narrow, terminating variably in front. 
Labial Palpi.—Two-jointed. : 
Mentwm.—Variable in shape. : 
Thoracic and Abdominal Segments.—Of the same general form and consistence. The 
thoracic segments usually longer and larger than the abdominal. The latter have fre- 
quently tubercles on the margins, and bristles or small tubercles or pit ox regularly 
G2 
