200 BULLETIN 154, UNITED STATES NATIONAL MUSEUM 



red in the ventral coloration. Therefore, true intergradation is to 

 be expected from a point still farther south. 



A more definite kind of approach is apparently seen in tAVo speci- 

 mens from San Marcos Island which lies in the Gulf of California. 

 In these (C.A.S. Nos. 51597, 50502) the tail is light as in 'i-uhidus, 

 but yellowish as in tessellatus. The dorsal markings are those of 

 mlndus rather than those of tessellatiis. These intergrades seem to 

 mark the northern limit of I'uhidits^ for all more northern specimens 

 examined (including those from San Bartolome Bay) are nearer 

 to tessellatus. 



On the basis of this evidence of intergradation, ruljidus is here 

 returned to its original subspecific status. 



Cneimdo'plioi'nis vandetiburgM., described by Dickerson (1919) from 

 Carmen Island, was apparently based on an irregularity of the 

 dark spots on the body. An examination of the type shows it to be 

 a rather typical young specimen of t'ubidus. The under surface of 

 the tail is red and the transverse element is beginning to l)c 

 emphasized in the dorsal pattern. Van Denburgh (1922, p. 549), 

 said that " After carefully comparing two specimens from Carmen 

 {vandenburghi) and five from Danzante Island {ruMdus) with two 

 of Cope's original series from Margarita Island (ruhidus) 1 believe 

 them to be identical in every respect." This is the final conclusion 

 reached by the writer after an examination of all of the specimens. 



Diagnosis. — Specimens of rubidtis may be distinguished from 

 tessellatus by the presence of red or pinkish in the ventral coloration, 

 especially of the tail, and from celeHpes by the presence of a definite 

 transverse element in the arrangement of the dorsal markings. In 

 ruhidus., crossbars are early developed and long retained, and the 

 longitudinal dark fields are usually confluent only in the youngest 

 specimens. The dark markings on the sides of the head of riibidus 

 are few, usually very light or absent, and often brownish, instead of 

 deep black as in celeHpes. 



Description. — Snout rather blunt; nostril anterior to nasal suture; 

 anterior nasal usuall}^ not in contact with second upper labial; 

 supraoculars 3-5; supraocular granules variable in position; fronto- 

 parietals normally 2; parietals normally 3; occipitals small; 

 anterior gulars moderate, uniform or somewhat enlarged centrally; 

 posterior gulars small, uniform; mesoptychial scales small, median 

 largest, arranged in 4-T transverse rows. 



Body elongate; ventral plates in 8 longitudinal and 30-36 trans- 

 verse rows; dorsal granules small to moderate; limbs well developed; 

 brachials 4-7; antebrachials 2-5; brachials and antebrachials more 

 or less continuous at a point of contact; postantebrachium with 

 small or slightly enlarged granules; femorals 7-10; tibials 3-5; 



