NO. 1101. PBOCEEDINGS OF THE NATIONAL MUSEUM. 71 



Infraorbital foramen large, bounded posteriorly by a very slight bar of 

 bone. Lachrymal foramen large, situated in front of and above the 

 infraorbital. Horizontal ramus of mandible curved upward anteriorly 

 and downward posteriorly. Coronoid process quadrate, with straight 

 posterior margin. Angle similar but smaller. 



TEETH. 



Dental formula: i, | ; c, 1; pm, |; m, §; total, 44. 



First superior incisor very large, broad, and flatfish; somewhat 

 inclined inward and connivent at the inner angle, notched in the mid- 

 dle and furnished with a small but distinct external accessory cusp. 

 Second and third incisors, canine, and first and second premolars 

 simple, conical, slightly curved, and compressed. Third premolar simi- 

 lar, but with a small compressed posterior accessory cus]). Tlie canine 

 is the largest of these simple teeth and the first premolar the smallest; 

 the second and third premolars are successively larger. The second and 

 third incisors are similar, but the third is larger than the second. The 

 fourth premolar is large, triangular, compressed, with a small anterior 

 accessory cusp, a posterior trenchant margin terminating in a basal 

 tubercle, and an internal basal cusp, or heel, which is bifid. The first 

 molar is hirgest, the second intermediate, and the third smallest. They 

 are furnished with large W-shaped external cusps as in the other 

 genera and a prominent internal basal ledge, which is trilobed (or 

 quadrilobed in the first molar). In the last molar the posterior por- 

 tion of tlie external cusp is aborted. 



The first lower incisor is similar to the upper one but smaller. The 

 six succeeding teeth — namely, the second and third incisors, the canine, 

 and the first, second, and third premolars — are simple and conical. All 

 are subequal except the second incisor, which is larger and canine-like 

 with an anterior trenchant margin. The premolars have obsolete basal 

 tubercles. The fourth premolar is similar to the others, but furnished 

 with more conspicuous anterior and i^osterior tubercles and a similar 

 internal one. The first and second molars are equal in size and the 

 third about one-third smaller. The are W-shaped in transverse section. 



The internal cusps are very prominent. The first molar has a distinct 

 postero internal basal tubercle, and the second molar similar tubercles 

 both anteriorly and posteriorly. The anterior internal cusp of the first 

 molar is bilobed. 



SKELETON. 



The vertebral formula of Parasealops breiveri, as determined from 

 a skeleton in the National Museum collection, and two others in the 

 collection of Dr. Merriam, is as follows: c, 7; d, 13; 1, (3; s, G; ca, 13; 

 total, 45. The last caudal is rudimentary. 



There are eight intervertebral ossicles, the most anterior of which is 



