HERPETOLOGY OF JAP.VN. 



221 



burg Museum (Xo. 1195) was collected by Doctor Warburg in 

 Okinawa shinia. 



List of specimens of Lciolupisnia latcrule. 



o Description, p. 219, figs. 190-192. 

 Genus LYGOSAURUS" Hallowell. 



18(J0. Lyiiosaurns Ii.\LLO\VEU., Proc Phila. Acad., 1860, p. 4!)(i, (type, L. pdlo- 

 plcurus). 



Only one species known, which is confined to the Iliu Kiu Archi- 

 pelago. 



Hallowell's Lygosaurus felloi^leurus has been relegated to that vast 

 mass of species (more than 150) which some anthers call Lygosoma, 

 and more particularly to the section or subgenus Homolepida. The 

 peculiar scutellation on top of the head, as well as the retractility 

 of the claws, make the retention of the genus Lygosaurus imperative. 



In the first place, the parietals have been reduced so in size as to 

 differ but very little in appearance from ordinary nuchals; further- 

 more, the interparietal, with the parietal foramen, is pushed so far 

 forward that the latter is on a line with or anterior to the posterior 

 edge of the orbit ; the frontal is also pushed ahead of its normal posi- 

 tion so as to separate the prefrontals widely and reduce them to 

 small scutes on the canthus rostralis. Its greater portion overlies, 

 in fact, the nasal bones. Moreover, instead of a single frontal there 

 are two, the posterior frontal being apparently composed of the 

 posterior portion of the original frontal and the anterior portion of 

 the fronto-parietals. It thus comes to pass that the posterior frontal 

 and the interparietal are widely in contact, while the fronto-parietals 

 are as widely separated. My preference to regard this unpaired 

 shield which lies between the supraoculars as a second frontal rather 

 than a third and unpaired fronto-parietal is due to the fact that the 

 two frontals together are in contact with only the two anterior supra- 

 oculars, which is the normal arrangement in allied genera with only 

 one frontal. Another reason is the fact that in two specimens exam- 

 ined by me the two frontals are actually fused. This extraordinary 

 arrangement of the cephalic plates will be best understood by a glance at 

 the appended figure(fig. 193). Hallowell's original description should 

 be read in the light of the above interpretation of the scutes, so that 

 his internasal becomes the fronto-nasal ; his fi-onto-nasal is the 

 anterior frontal ; his frontal becomes the posterior frontal ; his ' ' ihter- 



oFrom X-Cyog, flexible twig; 6avpo<;, lizard. 



