4 
last few days, when, having determined to clean them, and mount them on card, I 
then perceived that they were distinct species. The history of the specimen is un- 
known to me, but I believe it was given me as the O. sulcatus. Both the insects 
exhibited, it would appear, are known only as inhabitants of South Europe. It is 
hoped that this notice will induce our Entomologists to examine their British col- 
lections, with the view of ascertaining whether they contain these species, and can 
furnish us with any information respecting them. 
“‘ Psammodius porcicollis (Aphodius porcicollis, [lliger, Magazin fiir Insectenkunde, 
ii. p. 195, 2, 1803) has the same thickly tuberculated head, the transverse ridges on 
the thorax, and strongly sulcated elytra, as in P. sulcicollis ; its colouring, moreover, 
is the same, being pitchy black, with the legs and fore part of the head dull rufous; 
but it differs in being decidedly larger. The oblique ridges seen on the head of P. 
sulcicollis, and which converge and meet at an angle near the hinder part of the head, 
are scarcely to be traced in P. porcicollis, nor are the large punctures which are 
visible in the former insect on the back of the head. The thorax is relatively more 
ample in P. porcicollis, and the coarse punctures in the transverse sulci are more nu- 
merous and more evident, especially on the hinder part of the the thorax, behind the 
posterior transverse ridge: the elytra are more strongly suicated, and the punctures in 
the sulci are larger, and separated from each other, for the most part, only by narrow 
transverse ridges; the interstices of the strie are broader; and lastly, the outermost 
interstice is continued from the base of the elytron only about half-way towards the 
apex, so that the two outermost striz become confluent beyond that part. The corre- 
sponding interstice in P. sulcicollis is at first (near the humeral angle of the elytron) 
united for a short distance with the much more prominent interstice which is nearest 
to it, and then is free, and extends to the apex of the elytron. 
“« Onthophilus exaratus, De Marseul, Essai Monographique sur la Famille des His- 
térides, Ann, de la Soc. Ent. de France, 3me série, iv. p. 552, sp. 2. Hister exaratus, 
Illig. Magaz. vi. 48, 25 (1807).— The insect exhibited is as large as the largest speci- 
mens of O. sulcatus, and is placed by De Marseul and others in the section of the 
genus in which there is an odd number of longitudinal ridges (5) on the dorsal surface 
of the thorax,—a section which includes our O. sulcatus; whilst our common smaller 
species, O, striatus, is placed in the section having an even number (6) of ridges on 
the thorax. Of course in the former case there would be a mesial ridge, and the spe- 
cies of the second section would be destitute of a mesial ridge, and thus two distinct 
types of sculpturing might be said to exist in these very closely-allied insects,—a pe- 
culiarity which would not be in accordance with our general experience. The O. exa- 
ratus, however, shows that such is not the case. All the species have six ridges. The 
differences in the three species are, that in O. striatus the four ridges on the dorsal 
surface of the thorax are equidistant and entire, and they extend from the base to the 
apex of the thorax ; the other two ridges are short, confined to the hinder half of the 
thorax, and situated, one on each side, rather nearer to the lateral margin than to the 
dorsal ridges. In the other two species the above so-called four dorsal ridges are 
interrupted, the outer pair vanishing on the anterior third of the thorax, and the 
middle pair interrupted about midway between the base and apex uf the thorax, and 
reappearing, more widely separated, on the fore part. In O. sulcatus the two middle 
ridges are almost united into one ridge, being separated only by a slender impressed 
line. In O. exaratus the two corresponding ridges are distinctly separated by a shal- 
low, densely punctured groove ; the space between them and the nearest adjoining 
