A NEW GENUS OP ENGYSTOMATIDiE — FRY. 103 



are moderately large, and broader behind than in front ; the 

 parietal fontanelles (PI. ix., fig. I, p. fon.) are much smaller, 

 about one-quarter the size of the frontal, and are sub-circular 

 and more widely separated ; they are separated by half their 

 width from each other, and from the frontal fontanelles. Posterio- 

 laterally the frontoparietals project slightly on to the auditory 

 capsules, forming a small postorbital process, and then run back- 

 wards and inwards along the inner border of the anterior 

 semi-circular canal. Their posterior edge is raised slightly into a 

 bony ridge, and is produced into several weak upward projections. 

 In the inter-orbital region they project laterally and form a ridge 

 which terminates anteriorly on the ethmoid. 



The nasals (na.) are thin, slightly bilobed, and strongly arcuate 

 bones. They form a median suture, thus differing from Ghaperina. 

 Their hinder edge though sinuate is transverse, which applies 

 also to the fronto- and ethmo-nasal sutures. In front the nasal 

 region is narrow and emarginate, and the bulging of the down- 

 turned nasal roofs gives a somewhat bilobate appearance to the 

 snout. The premaxillse are doubtfully visible from above. The 

 nasal is united by the cartilaginous sub-nasal lamina to the 

 maxillae and premaxilla?, which cartilage is pierced near the 

 nasal process of the premaxilla? by the nostril. This cartilage 

 is undifferentiated owing to the bad condition of the specimen 

 dissected, and the labial cartilages are lost. The nasal sends off 

 a spike posteriorly which rests on the outer third of the palatine. 

 The septum nasi (PI. ix., fig. 2, s.n.) is rather delicate. 



The large parasphenoid (PI. ix., fig. 2, psph.) reaches practically 

 the limit of its development, underlying the whole of the basis 

 cranii, and auditory capsules. In a few respects this bone differs 

 from the same in Chaperina fusca. It forms a suture with the 

 palatines which in Chaperina underlie it ; the length is only nine- 

 elevenths as long as the greatest width, while in Chaperina it is 

 sixteen-seventeenths. It enlarges a little in the interorbital 

 region but narrows again slightly in front of the auditory capsules. 

 The posterior boi'der slants obliquely backwards from the lateral 

 otic extremity almost to the foramen magnum. 



The "girdle-bone," sphenethmoid or ethmoid (eth.), is well 

 developed and bounds the whole of the anterior third of the 

 cranial box, but is visible externally only on the sides anterior 

 to the orbitosphenoid cartilage, dorso-laterally, and as a diamond- 

 shaped area situated between the nasals and the frontoparietals. 

 It projects anteriorly beyond the palatine expansions into the 



