Posterior margin of the fifth segment simple. 
Emargination of the sixth segment <j as wide as deep............- capito 
Emaryination twice as wide as deep.............0.2+..- ..... flavicornis 
PLViuan mA Ge tOnGen tam THE PLOLMOLAK s.rcle lois « « sictounieis <urisiarayslas o.«'</s (ea 2)86/6 cinctus 
In his original description of pad/ipes, Gravenhorst does not allude 
in any way to the sexual charactérs of the male, and his description is 
perfectly applicable to either pa/lipes or capito; the table will therefore 
serve to establish these species in their mutual relationship. Cimc/us was, 
two years after Say’s publication, described by Nordmann (Symb. ad 
Mon. Staph., p. 150), as Cryptobium latericola. This was erroneously 
printed C. /atebricola by Erichson. and so copied by all the more recent 
authors, perhaps under the very plausible assumption that J/a/edricola is 
what Nordmann intended to write. /Zavicornis Lec., is a smaller species 
with decidedly narrower head ; it is rare. 
The following new genera are perhaps worthy of description on this 
occasion : 
MEGASTILICUS na. gen. 
Body robtst, sub-depressed. Head rounded, borne on a very slender neck. 
Eyes rather small. Antenne very short, compact, slightly robust, scarcely perceptibly 
incrassate. Labrum large, broadly emarginate in the middle at apex, the emargin- 
ation bidentate. Maxillary palpi very small, moderately robust ; third joint cylindrical, 
about twice as long as the second, truncate at apex; fourth joint small, subulate. 
Legs long and slender ; tarsi cylindrical, the anterior not in the least dilated in the 
male ; posterior nearly as long as the tibie, with the first four joints decreasing 
gradually in length, the first shorter than the next two combined and slightly longer 
than the fitth. 
This is a myrmecophilous genus, peculiar in the structure ‘of the 
maxillary palpi, in this respect having no near allies which I have seen. 
The body is remarkably robust. 
M. formicarius n. sp. 
Rufo-ferruginous ; head and abdomen piceous ; entire upper surface densely 
granulato-reticulate, rather dull and covered somewhat densely with short erect and 
very robust spinules ; abdomen smoother and not granulate. Head as wide as long, 
very slightly wider and longer than the prothorax, the latter hexagonal, widest much 
before the middle, feebly narrowed toward base, the latter transversely truncate. 
Elytra slightly wider than long, longer than the prothorax and, toward apex, nearly 
twice as wide. Abdomen short and brvad, in the middle slightly wider than the 
elytra ; sides arcuate. Length, 5 mm. 
New Jersey ; Massachusetts. 
The male has the’apex of the sixth ventral segment deeply sinuate. 
I am indebted for my first specimen of this very singular insect to 
my friend Mr. W. Jiilich, of New York ; subsequently I received several 
others through the kindness of Mr. F. Blanchard, of Lowell, Mass. ; 
whose MS. name I have adopted for the genus. 
