no. 1762 A \i:\V FOSSIL CROCODILE (lILMOltH. 487 



18 mm. by the inner border of the orbit. The posterior upper sur- 

 face is ornamented with well-defined pits, smaller than those found 

 on the same surface of the parietals. These pits vary in size and 

 shape from subround to elongate-oval, being arranged in transverse 

 rows and separated by ridges narrower than themselves; none are 

 confluent. The larger pits have their greatest diameter transversely . 

 The median anterior portion is without decided ornamentation, as 

 best shown in a detached frontal (Cat. No. 6542, U.S.N.M.). The 

 whole of the under surface is smooth except an area on either side 

 posteriorly for the sutural union with the alisphenoids, where it forms 

 a considerable part of the roof of the cranial cavity. Between the 

 alisphenoids is a median longitudinal depression, which carries the 

 sense organs to the olfactory lobes of the brain. This groove trav- 

 erses the whole length of the bone, widening anteriorly to the front o- 

 prefrontal suture. Posteriorly, this suture can only be made out on 

 the inner orbital surface where it occupies approximately the same 

 position as in ('. americanus, and on the orbital side runs obliquely 

 downward and forward. 



The squamosal meets the quadrate and exoccipital below and forms 

 part of the roof of the external auditory meatus. Lt is pitted above, 

 and, with the prefrontal, forms the outer boundary of the supra- 

 temporal fossa. The postfrontal unites as usual with the jugal by a 

 strong postorbital bar. The shape or extent of the nasals, pre- 

 frontals, or lachrymals can not be determined in this specimen, as all 

 of the sutures are obscure. These bones are roughly sculptured. 

 That portion of the preorbital region which is preserved in this speci- 

 men is depressed medially and at the sides is bent sharply downward 

 and inward to the aveolar border; more anteriorly the direction of the 

 side is only downward. As a whole, the snout is bent somewhat 

 upward, so that in profile the anterior portion is slightly concave 

 above. (See PI. 25.) The cranium above and extending down the 

 sides on the jugal, maxillary, and premaxillary bones is beautifully 

 sculptured with pits of irregular size and shape, inclosed by reticular 

 ridges of varying widths. The sculpturing is most rugose on the pos- 

 terior elements, particularly on the jugal and posterior half of the 

 maxillary; medially on the nasal-, are long, broken, longitudinal 

 grooves, while on the muzzle the pitting as a rule is finer and more 

 shallow, and lacks the definition of the posterior surfaces. 



Over the aveoli for the ninth and tenth teeth, the lateral borders 

 of the maxillae are swollen outwardly, but anteriorly the muzzle 

 gradually contracts to the elongated notch which receives the lower 

 canines, this being the narrowest part of the skull, measuring 50 nun. 

 in transverse diameter. In advance of the notch the premaxillae 

 swell out into a moderately broad but evenly rounded nose. The 

 widest part, over the fourth premaxillary teeth, measures 58 nun. 



