The species is named in honor of the late Professor Chester Stock, under whose direction the fossil materials from San Josecito Cave were obtained, and who, at the time of his death, was studying the mammalian fauna from the cave.
Eptesicus cf. grandis (Brown)
Referred material.—One rostrum, with P4-M3 on the right side and P4 only on the left, LACM (CIT) 2990.
Remarks.—This specimen is referred provisionally to E. grandis. The dentition is larger and heavier, and the ridges and depressions on the dorsal surface of the rostrum are more pronounced than in Recent E. fuscus. The P4-M3 length is 6.1 (approximately 6.1 in the holotype of grandis, less in fuscus); least interorbital constriction, 4.2 (4.3 in the holotype of grandis, more in fuscus); breadth of rostrum between infraorbital canals, 6.4; breadth across P4, 7.3.
Table 1.—Cranial measurements of two species of Desmodus.
| Catalogue number or number of specimens averaged | Greatest length of skull | Condylobasal length | Zygomatic breadth | Breadth of braincase | Least interorbital constriction | Breadth of foramen magnum |
| Desmodus rotundus murinus, La Mula, 13 mi. N Jaumave, Tamaulipas | ||||||
|---|---|---|---|---|---|---|
| 10 (3 ♂, 7 ♀) Ave. | 24.3 | 21.4 | 12.0 | 12.1 | 5.5 | 5.2 |
| Max. | 24.9 | 22.0 | 12.5 | 12.5 | 5.6 | 5.3 |
| Min. | 23.9 | 21.0 | 11.7 | 11.9 | 5.3 | 5.1 |
| Desmodus stocki, San Josecito Cave, Nuevo León | ||||||
| 2946 | 27.3 | 24.5 | 14.2 | 6.1 | 5.8 | |
| 2947 | 13.6 | 5.7 | ||||
| 2948 | 24.3 | 13.9 | 6.2 | 5.3 | ||
| 2949 | 24.7 | 13.9 | 6.1 | 5.5 | ||
| 2950 | 14.1 | 13.5 | 5.7 | |||
| 3127 | 13.5 | 6.0 | 5.7 | |||
| 3128 | 26.5 | 13.5 | 6.2 | 5.5 | ||
| 3129 (type) | 28.2 | 24.5 | 13.7 | 5.9 | 5.7 | |
| 3940 | 27.4 | 24.4 | 13.8 | 6.2 | ||
| 3941 | 24.6 | 14.0 | 13.7 | 6.0 | 5.6 | |
Brown (1908:174) originally named grandis as a subspecies of fuscus. Gidley and Gazin (1938:11) considered it a distinct species. Whether grandis is only a subspecies of E. fuscus or a separate species, grandis is closely related to fuscus, and probably is ancestral to it.
Lasiurus cinereus (Palisot de Beauvois)
Referred material.—One cranium, lacking basioccipital, tympanic and mastoid regions, and most of the dentition, having only M3 on the right side and M2-M3 on the left, LACM (CIT) 3160.