158 CALIFORNIA ACADEMY OF SCIENCES. 



mixed black and white, reaching to the shoulders; tail 

 white below and on sides, the dark brown dorsal streak 

 covering about one-third of its circumference. 



Cranial characters. — Posterior process of the intermax- 

 illaries extending well beyond the nasal bones, reaching 

 to opposite the posterior part of the anterior upper molar ; 

 interparietal wdde and not very long, wdth an evident 

 posterior angle. Compared wnth N. vicxicana and N. cal- 

 if arnica, the cranium is at once conspicuous by its much 

 more inflated auditory bullae. It has also a deeper snout, 

 less projecting nasal bones, and deeper post -palatine 

 notch. It agrees wath califortiica in the characters sep- 

 arating the latter from niexicaua,, having short incisive 

 foramina, backwardly- produced nasal processes of the 

 intermaxillaries, and a decided posterior angle to the in- 

 terparietal. The mandible is heavier and more strongly 

 ridged than in either of the species just mentioned ; the 

 coronoid and condyloid processes are shorter and thicker, 

 the latter hardly extending above the former, and the in- 

 cluded notch is broadly rounded. 



Cranial measurements of type. No. 1336. 



Basilar length of Hensel, 36 mm. 



Greatest zygomatic breadth, 22.5 mm. 



Least interorbital width, 5. mm. 



Length of nasals, 17. mm. 



Distance from incisors to incisive foramina, 3.5 mm. 



Length of incisive foramina, 8.3 mm. 



Length of rostrum from front of zygoma, 11. mm. 



Height of rostrum at front of zygoma, 9. mm. 

 Neotonia albigula agrees in size and general propor- 

 tions with Neotonia niexicana, but differs in the following 

 respects: 



