Psyche 
[June 
114 
ular, intervals subconvex; intervals without discal punctures; meta- 
thoracic wings vestigial. Aedeagus about as in M. tlamayaensis, 
2.12 mm in holotype. 
Holotype male, Sotano de la Joya de Salas, 25 km west of Encino, 
elevation 1600 meters, Tamaulipas, Mexico, 3 June 1965, David 
McKenzie, John Fish, and Orion Knox leg. Three paratypes from 
the same cave, two on 3 June and one taken 23 January 1965 by 
D. McKenzie. A fourth paratype, “30 ft. down in sinkhole”, Rancho 
del Cielo, 6 km NW Gomez Farias, Tamaulipas, 1 July 1965, L. E. 
Gilbert. 
Like M. veraecrucis , this species seems to be an incipient tro- 
globite, with an elongate body, very small eyes, and vestigial meta- 
thoracic wings. Mr. James R. Reddell provided the following 
information: “The three Mexisphodrus were found in the same vi- 
cinity of the first specimen — within a well-illuminated area of about 
4 square yards on the floor of the entrance shaft. Decaying animal 
carcasses were near-by. This was also a very wet portion of the 
rocky floor area, which was 20 feet by 75 feet. All of the beetles 
had apparently burrowed to positions beneath shoe-sized rocks par- 
tially embedded in mud. When uncovered and disturbed they ran 
rather rapidly. The dry season may be limiting their activity in 
this locale; the area is well ventilated and subject to drying. But 
none were discovered in the moist lower portions of the 1 cave where 
other troglobites were common.” 
TABLE 1 
MEXISPHODRUS SPP., HOLOTYPES, 
COMPARATIVE MEASUREMENTS (Millimeters) 
M. veraecrucis 
M. tlamayaensis 
M. profundus 
Barr 
n. sp. 
n. sp. 
Total length 
18.1 
11.3 
12.1 
Head length 
3.2 
2.1 
2.1 
Head width 
2.0 
2.1 
2.1 
Antenna 
10.6 
6.8 
8.0 
Eye diameter 
0.6 
0.7 
0.4 
Pronotum length 
3.4 
2.1 
2.3 
Pronotum max. width 
3.4 
2.4 
2.5 
Pronotum apex width 
2.4 
1.8 
2.0 
Pronotum base width 
2.8 
1.8 
1.9 
Elytra length 
10.0 
6.1 
7.0 
Elytra width 
5.5 
4.0 
3.7 
Aedeagus 
3.3 
2.2 
2.1 
