MAY 4, 1923 COCHRAN: NEW LIZARD OF GENUS SCELOPORUS 185 
pails over tympanum to shoulder; ventral disk plainly marked by dermal 
olds. 
Dimensions.—Tip of snout to vent, 36 mm.; tip of snout to posterior edge 
of tympanum, 13 mm.; greatest width of head, 13 mm.; fore leg from axilla, 
19 mm.; hind leg from vent to heel, 26 mm.; hind leg from vent to tip of fourth 
toe, 49 mm. 
Coloration (in alcohol).—Body dark bluish-gray above, becoming lighter 
on the sides; the sharp rim on the snout white; the head dark gray with a 
blackish bar between the eyes; a black band from eye across tympanum to 
shoulder; arms and legs light with darker bands and markings; a white line 
on the posterior femur; underside whitish, the throat finely sprinkled with 
pale gray. is 
Remarks.—This frog is closely related to Leptodactylus albilabris from 
Porto Rico. The snout is shorter and broader, and the projecting edge on 
the upper lip is far more pronounced. Then, too, the hind legs are shorter, 
and the examination of the mouth reveals a deeply incised tongue, while the 
tongue of L. albilabris is only slightly nicked behind. 
ZOOLOGY.—A new lizard of the genus Sceloporus.' Doris M. 
Cocuran, National Museum. (Communicated by Dr. L. 
STEJNEGER. ) 
While identifying the lizards collected in Mexico. by the Biological 
Survey and now in the United States National Museum, I came 
upon a species of Sceloporus which seems to be new to science. 
Sceloporus nelsoni sp. nov. 
Diagnosis.—Lateral scales directed obliquely upwards and backwards, 
and passing gradually into the dorsals; series of femoral pores widely separated, 
not meeting on the preanal region; tail strongly compressed; head-shields 
smooth; two rows of granular scales between supraoculars and supraciliaries; 
femoral pores 15 to 20. 
Type.—U. 8. N. M. No. 47676; Plomosas, Sinaloa, Mexico; July 18, 1897; 
Nelson and Goldman, collectors. 
Description.—Head-shields smooth; frontal ridges fairly prominent; frontal 
transversely divided, in contact with the interparietal, which is a little broader 
than long; a single large parietal shield on each side of the interparietal; 
fronto-parietals in contact with last two supraoculars; two canthal scales; 
five transverse supraoculars, bordered inwards by an incomplete series of 
small scales, and separated from the supraciliaries by two rows of almost 
granular scales; five scales, not larger than those before them, form a denticu- 
lation on the anterior border of the ear; dorsal scales much larger than 
ventrals, strongly keeled, mucronate, forming slightly converging series; 
35 scales between the interparietal shield and the base of the tail; 9 scales, 
taken in the middle of the back, correspond to the length of the head; ventral 
scales small, smooth, bi- or tricuspid; about 36 scales around the middle of 
the body; the adpressed hind limb reaches between ear and eye; tibia as 
long as distance between end of snout and ear; the distance between base of 
1 Published by permission of the Secretary of the Smithsonian Institution. 
