1914] Mann—Myrmecophilous Insects from Mexico 179 
Terapus mnizechi Mars. 
Two specimens were taken at San Miguel in nests of Pheidole 
vasleti var. acolhua Wheeler. In the place where these were found 
was a stone fence extending for about a half mile, along which 
were literally hundreds of nests of acolhua. Although I made 
several visits here and searched many nests in other localities for 
the beetles no more were found. It is evidently exceedingly rare 
locally but has a wide distribution in Mexico. : 
Terapus infernalis Fall. 
Melaneterius infernalis Fall. 
An account of this species has been given by Wheeler (PsycuE 
XVIII, 1911, p. 112-114) who found a number of specimens at 
Pasadena in company with Pheidole hyatti Emery. One of these 
was studied by Bickhardt (Psycur XIX, p. 97, 1912) who found 
that the beetle and most of the details of Wheeler’s figure agreed 
with Marseul’s description and figure of mnizechi, to which species 
he referred it. Recently, through the kindness of Mr. J. H. 
Arrow, I was able to examine in the British Museum a specimen 
of mnizechi from the Federal District of Mexico. This was un- 
doubtedly the same as the San Miguel specimens, and these are 
specifically quite distinct from the Southern California form. 
In infernalis the propygidium is feebly punctate above and more 
coarsely beneath, with the upper, smoother portion much smaller 
than the lower, and there is no sharp line between the two parts. 
In mnizechi the upper portion is smooth and shining, the lower 
punctured and opaque, and each part is in strong contrast to the 
other. The upper part is proportionally larger than it is in infer- 
nalis. The latter species is smaller, measuring two millimeters 
while mnizechi measures three. 
Family ScaRABHID®. 
Cremastocheilus, subgenus Myrmecotonus noy. 
Type: Cremastocheilus knochii Lec. 
I propose this subgenus to contain those species which have the 
mentum angulate behind. This character is correlated with the 
geographical distribution of the species, all of the species in this 
group inhabiting the middle and far West. C. wheeleri Lec. 
