214 BULLETIN 199, UNITED STATES NATIONAL MUSEUM 



DASIA MICROCEPHALUS (Hallowell) 



Euprepis microcephalus Hallowell, Proc. Acad. Nat. Sci. Philadelphia, vol. 8, 

 1856, p. 155; Trans. Amer. Philos. Soc, ser. 2, vol. 11, 1857, pp. 79-80. 



Diploglossus microcephalus, Boulenger, Catalogue of the lizards in the British 

 Museum, vol. 3, 1887, p. 504, 



[Dasia] microcephalus, Smith, Proc. U. S. Nat. Mus., vol. 92, 1942, pp. 369-370 



Type. — Acad. Nat. Sci. Philadelphia; W. H. Keating collector. 



Type locality. — Mexico. 



Remarks. — The first words in Hallowell's original description are 

 "Syn. Scincus ventralis, Peale and Green." Then follows the descrip- 

 tion. We believe the citation of Peale and Green's name as a synonym 

 (an earlier one at that) of Hallowell's own name could be construed 

 to make his name unavailable, that is, actually a synonym of Scincus 

 ventralis and thus a part of the synonymy of Gerrliunotus I. liocephalus. 

 The fact remains that the animal described by Hallowell, and pre- 

 sumably the type of his name, is far different from Gerrhonotus. We 

 recommend association of the name with the species represented by 

 the animal described and not assignment to the synonomy of Scincus 

 ventralis. 



The type is not in good condition (portions of the head mutilated), 

 but appears to belong to a non-American genus, probably Dasia.^ 

 It may possibly be one of the original series of three specimens of 

 Peale and Green's Scincus ventralis, since only two of them are now 

 present in the series labeled as cotypes, and thus would be explained 

 Hallowell's citation of Scincus ventralis as a synonym of his species. 

 It is also possible that a confusion of specimens occurred, the original 

 Gerrhonotus being exchanged for the present type of microcephalus, 

 which Hallowell erroneously thought was one of Peale and Green's 

 cotypes. One of these alternatives must be true: Either a peculiar 

 skink, unloiown except by the type of microcephalus, occurs in Mexico, 

 or else some shift of specimens occurred in the Philadelphia Academy 

 collections between 1830 and 1856. We favor the latter alternative. 



Still another species is represented by a specimen questionably 

 secured in Mexico, whUe the range of the species is suspected of being 

 entirely extralimital. 



DIPLOGLOSSUS MONOTROPIS (Kuh!) 



Diploglossus monotropis (Kuhl), Beitrage zur Zoologie und vergleichende Ana- 

 tomic, 1820, p. 128. 



The species is known to occur from Costa Rica to Ecuador. The 

 U. S. National Museum has one specimen questionably from "Colima." 

 Occurrence in Mexico is highly questionable. 



> We are indebted to Dr. E. R. Dunn for this information. 



