One of the peculiarities of the skull of this species, sharply 

 differentiating it from other skulls at my disposal, is the presence c 

 a high nail- like crest, passing along the suture between the para- and 

 sisphenoids. The greatest height of this crest is equal to the widt 



the parasphenoid . The strong development of such a bony crest on 

 2 lower surface of the para- and basisphenoids indicates significant 

 ^elopment of muscle, passing along both its sides. 



auai. y i-y 

 presence of 

 s para- and 



basisphenoids. The greatest height of this crest is equal to the width 



of the pai 



trie lOWer ouLi-a^-c *->±- llic: pcii-ci" aiiu uaa^opiicuuj 



development of muscle, passing along both its 



Even the palatine bone, which by its form has little in common with 

 the same bone of other species of Ancistrodon , deserves to be noted. It 

 has not yet been mentioned that it carries no more than one tooth (the 

 skulls of other species examined by me have no less than three -- 

 figure a). The bone has a very distinctive form owing to the presence on 

 it of a long, gradually tapering \$p&y- appendage, directed upward and forward 

 (figure b). This structure on the palatine bone of this species was first 

 noted by Peters (1862), who put rhodostoma into the genus Tisiphone , which 

 had been established by Fitzinger (1826) for a single species of American 

 snake. Peters included a number of other generic synonyms- Among other 

 craniological characters, which prevent placing this species in the genus 

 Ancistrodon , there should be pointed out the structure of the transverse 

 bone, the expanding caudal end of which is almost perpendicular to its 

 anterior, elongated lever- like end, resting against the upper maxillary 

 bone. Furthermore, it is necessary to note the absence on the lower 

 surface of the prefrontal bone of 'any noticeable opening, through which 

 might pass blood vessels and nerves, and larger or smaller slit- like 

 openings for the passage of an optic nerve. I might cite here other 

 characteristics, less important, which I consider testify to the fact 

 [p. 792] that this species is included in the genus Ancistrodon completely 

 artificially; according to the structure of its skull, it is very remote 

 from the genus Ancistrodon , and so it must be put into another genus. 

 According to the rules of international zoological nomenclature, it must 

 be called Cal loselasma , since in the year 186$ Cope proposed this name in 

 place of the name Leiolepis , already used for the genus of lizards. I 

 will mention that Cope considered Calloselasma as a subgenus of the genus 

 Tr igonocephalus , since it was based only on the absence of keels on the 

 scales in this species. ' «'■ •• 



The possibility is not excluded that other southern Asian species, 

 now in the genus Ancistrodon , will also be excised from it after 

 examination of their cranial osteology, and will prove to be related to 

 Cal loselasma. 



