MR. A. MURRAY'S MONOGRAPH OF THE FAMILY OF NITIDULARLE. 271 
the whole of the last three dorsal segments usually exposed. Legs rufous or piceo- 
rufous. 
The most distinguishing characters of this species are its short thorax, very broad 
behind and rapidly narrowed in front, with a deep curved impression at the base on each 
side of the middle, extending into the posterior angles. Something like this occurs in 
the variety lugens, which is supposed to come from Brazil; but the abdomen of that 
variety has only the last two segments distinctly exposed, and the curved impression on 
the thorax is less marked and interrupted. 
1 should have preferred to retain the name by which this species was first described 
(Cercus niger, Say); but as Say's description is scarcely recognizable, and Erichson’s 
name is thoroughly and universally established, I feel that I should be doing more harm 
than good to science by thus stretching too tightly the laws which regulate nomenclature. 
From Pennsylvania and the southern parts of North America; extending into 
Mexico. | 
The variety lugens is smaller and not so broad, the thorax is comparatively narrower, 
the basal curved fovea on each side of the thorax is less marked—almost confined to a 
deep oblique fovea in the posterior angles, the abdomen has scarcely more than two 
segments exposed above, and the legs are darker; but, on the whole, I have not thought 
the differences sufficiently great to warrant me in recording it as a distinct species. 
Believed to be from Brazil, but locality somewhat doubtful. Described from a single 
specimen, which I have placed in the British Museum. 
The variety which I have called perforatus may perhaps be a distinct species; but, from 
its general character and the style of its punctuation, I am inclined to think that it is the 
climatal variety of morio peculiar to Bahia. Its chief difference is the absence, or nearly 
so, of the curved depression on each side of the base of the thorax. It is not wholly absent, 
however, and there is a slight trace of the fovea in the posterior angles. Its thorax is con- 
siderably more closely punctate, the punctures smaller and more distinct; the scutellum 
is very thickly and distinctly punctate, except at the very apex; and the elytra are also 
more distinctly punctate, the rows of punctures more numerous and more irregular, 
anastomosing a little in some places. I do not see any other very marked difference. 
From Bahia. A single specimen was in Mr. Fry’s collection, which he has sacrificed 
to complete the collection of the British Museum. 
22. COLASTUS BREVICOLLIS. 
Valde affinis C. morioni: subdepressus, niger vel piceo-niger, nitidus, griseo Fig. 36. 
pubescens; thorace brevi, lateribus postea valde rotundatis; elytris ee 
striato-punctatis. Long. 2 lin., lat. 13 lin. 
Habitat apud flumina Amazonum. 
Very nearly allied to C. morio. Its chief difference is that the thorax is shorter, and 
is wide behind, for a greater space; the sides turn in rapidly near the posterior angles, 
which are somewhat obtuse, although, owing to the deep sinuation of the base, they are 
less so than might be expected from the rapid curve of the sides; there is no curved 
2N2 
