204 PROCEEDINGS OF THE ACADEMY OF [1894. 



IV. Eleven to thirteen rows of scales keeled. 

 Supralabials eight or nine; silvery with a wide blue dorsal band; 

 sometimes obscure in alcohol; smaller, L. alaetulla L. 



Supralabials nine ; robust ; uniform green ; smaller, 



L. occidentalis Gthr. 

 Supralabials nine ; green, head plates and scales all black bordered, 



L. marginatum Cope. 



Rupralabials nine; uniform green, the keels of the scales, except 



those of the median row, l)lack; size large, L. prcestans Cope. 



The L. ultramarinns is further characterized by the large size of 

 its eye, whose diameter equals the length of the muzzle to the rostral 

 plate, exclusive. The preocular reaches the frontal. Temporals 

 1-2, the anterior in contact with the inferior postocular only. Each 

 parietal is bounded by only three plates, with half of a median plate. 

 Seventh and eighth superior labials longer than deep. Nine infe- 

 rior labials, in contact with the genials up to the seventh. Post- 

 genials a little longer than pregenials. General form slender, tail 

 long, about one- third the total length, gastrosteges feebly angulated, 

 168; anal, 1-1; urosteges, 176. Total length, 1050 mm.; tail, 

 425 mm. 



Besides the colors above described there may be added, that the 

 preorbital labials are bordered with blue above, and the last two 

 labials are entirely blue. There are no stripes or lines of any kind. 



No. 108, PazoAzul; J. C. Zeledon. 



Pogonaspis ruficeps gen. et sp. nov. 



Char. gen. — Posterior maxillary tooth elongate, grooved; other 

 teeth numerous, small, present on the usual bones of the mouth. 

 Pupil round. Cephalic plates normal; two nasals, no loreal. One 

 pair of genials; anal plate and urosteges double. Scales smooth, 

 without apical fossa, extensively imbricate. In the hemipenis the 

 sulcus spermaticus is single, and the apex is calyculate. On the side 

 opposite the sulcus is a wide welt which is bordered by spines, whose 

 bases are connected by transverse flounces. Surface on each side of 

 welt coarsely spinous. 



This genus is probably more nearly allied to Tantilla than to any 

 other. The head of the only known species is rather more distinct 

 than is usual in that genus. The tail is probably elongate. It 

 diflers from TaidiUa in the large single genial plate. 



