1877.] 35 {[Cope. 
of the muzzle ; and that the brown band through the eye becomes obso- 
lete. Length M. 1.150; tail .346. 
The American species of Drymobius (Cope, Proc. Acad. Phila., 1860. 
560) are the following: D. margaritiferus, Schl.; D. reticulatus, Pet.; 
D. heathii, Cope; D. rappii, Gthr.; D. oceipitalis, Gthr.; D. pulehriceps, 
Cope ; D. dichrous, Pet.; D. boddaertii, Seetz; D. melanolomus, Cope ; 
D. biserialis, Gthr.; D. bilineatus, Jan.; D. pulcherrimus, Cope. 
12. Boa orTONII, Cope, sp. nov. 
This species is intermediate in character between the Boa constrictor and 
the B. imperator. It has the stout proportions of both species, while the 
squamation of the head is like that of the former, and that of the body 
resembles that of the latter. There are no large scuta on the loreal or 
orbital regions, and the scales of the head generally are characterized by 
their small size. The characters of the species are best brought out ina 
comparative table, which I give: 
Sect. I. 89-95 rows of scales on the body. 
Orbital ring not in contact with labials, gastrosteges 234 
eee RORIE MES 20th icc: 01ai¢ eae clsays Cael eis dale tng 0 aceerhs's ..B. constrictor. 
Sect. II. 55-69 rows of scales. 
«a Orbital series separated from labials by a row of scales; 
No large loral plate ; form stout ; g. 252, u. 53 ; labials 19 ; 
orbital ring composed of 19 scales ; 64 rows on body.......B. ortonii. 
aa Orbital ring reaching labials. 
No large loral plate ; stout; u. 56; 57-62 rows on body ; 
OUP ENO— Mies, fos s.c, 3 5: sie So6L sence Soneapepode moctalaeretotetare B. imperator. 
A loral plate as large as the orbit ; proportions as in the 
IOs o Ba ¢ Seen Ge ae eee BUM DOOR OOD Seca On OC UCR DS HoUne B. eques. 
No large loral plate ; form elongate; g. 272; u. 69..... B. diviniloqua. 
With the typical specimen I associate one from Greytown, Nicaragua, 
which agrees with it in the generally smaller size of the scales of the 
head and body than is foynd in the B. émperator, the usual Mexican species. 
It has 69 rows of scales ; 21 labials and 17 scales in the orbital ring ; gas- 
trosteges 242. ; 
No. 1 from Chilete, near Pacasmayo, 3000 feet above the sea. This spe- 
cies is dedicated to Professor James Orton, whose explorations of the 
western regions of South America have yielded such abundant results. 
13. STENOSTOMA ALBIFRONS Wazgler ; var. tessellatwm, Tsch. Fauna Pe- 
ruana, p. 46. 
As Jan remarks, this forms appears to be but a color variety of the S. a/- 
bifrons. 
No. 28, Chimbote Valley. 
LACERTILIA. 
14. PRocTOTRETUS MULTIFORMIS Cope, Journ. Acad. Phila. 1875. p. 178. 
No. 98; from La Raia or the divide which separates the waters of the 
Ucayali and those of Lake Titicaca ; altitude 14,000 feet. 
