30 University of California Publications in Zoology [^''ol. 21 



of hairs of upperparts approaching light pinkish cinnamon. Plumb- 

 eous hair bases of underparts taking a larger share in the general 

 coloration. A lesser infusion of long dark overhairs. 



Skull. — Best characterized by its large size, its widely spreading 

 zygomata, and narrow interorbital region. Dorsal profile considerably 

 flattened, slightly depressed interorbitally, but with region of greatest 

 convexity in plane with lacrimals. Occiput truncated very obliquely, 

 but not concealing the condyles. Brain-case subquadrate, its sides 

 rounded and truncated anteriorly by well developed postorbital 

 tuberosities. Longitudinal ridges extend along outer edges of par- 

 ietals, continuous posteriorly with lambdoidal ridge and anteriorly 

 with interorbital ridges. Interorbital ridges normally prominent. In 

 all specimens examined there is a distinct sulcus between the two, 

 though in some the ridges have nearly coalesced. Interparietal sub- 

 rectangular, its posterior border biconvex to a varying degree, with 

 lateral extremities squarely truncate ; anteroposterior diameter ex- 

 clusive of median projection one-half (or less) greatest transverse 

 diameter. Frontals convex posteriorly. 



A condition of unusual variability is exhibited by the rostral 

 region of this form. Normally the least depth behind incisors is 

 greater than width in same region. Nasals long, strongly spatulate, 

 emarginate or convex posteriorly. Nasals exceeded by ascending arms 

 of premaxillae which may extend beyond plane of lacrimals. Nasals 

 normally declining very little anteriorly. Vertical diameter of ante- 

 rior narial opening equal to transverse diameter. Plate forming outer 

 wall and continuous with lacrimal internally, complete superiorly, 

 though absent, as usual, inferiorly. Anteorbital foramen usuallj^ 

 rather wide as compared with its height. 



Occiput evenly convex or flattened, the median depth equal to 

 about 57% of greatest width across lambdoidal ridge of brain-case. 

 Foramen magnum subtriangular. Paroccipital processes well de- 

 veloped, directed more backward than downward, with their tips not 

 applied to bullae. Their posterior margins are continued upwards as 

 prominent ridges, terminating superiorly on lambdoidal ridge within 

 limits of lateral extremities of interparietal. Floor of brain-case 

 similar to that in other races of caMfornicus, though basioccipital 

 possesses a very sharp median ridge. Width of basioccipital at suture 

 between it and basisphenoid usually about one-third its median length. 

 Auditory bullae large, their posterior borders very obliquely trun- 

 cated. 



Palate with deep palatine sulci and well developed -lateral bridges. 

 Lateral pits fenestrated. Interpterygoid fossa narrow, the pterygoids 

 diverging posteriorly and occasionally with posterior margin of palate 

 acutely notched. Posterior palatine foramina moderate, though not 

 always open. Incisive foramina wide open, slightly wider in medial 

 regian, with ends rounded. 



Region of greatest zygomatic width slightly anterior to middle, and 

 with upper surface of maxillary arm of zygoma rather wide. Jugal 

 normally expanded and deeply mortised into maxillary root of zy- 

 goma. Zygomatic arches slightly notched at anterior junction with 

 premaxillae. 



Mandible large and robust. Ridge for masseteres laterales strongly 



