Coues.] 100 [June 16, 



rolled under like a scroll, to form an imperfect cylinder. Its only 

 articulation is with the ring-like prolongation of the frontal, upon 

 which its base is fitted by an oblique overlapping suture. * It projects 

 straight forward, like a horn, and enfolds the gristly and membran- 

 ous sense-capsule; no osseous ethmoid, or turbinate bones, exist. The 

 passage from the nasal chamber into the cranium is straight and open. 

 The palatines lack orbital plates or processes, are fused together 

 and to the vomer, and consist chiefly of palatine plates, united in 

 the usual way to the corresponding parts of the superior maxillary. 

 Their chief peculiarity is seen behind, in the place where the poste- 

 rior nares normally occur. The passage is blocked up by the fusion 

 of the bones into a solid plate that reaches the sphenoid centre and 

 forms a transverse wall. The palatines abut externally against the 

 descending processes of the alisphenoids; along the line of junction 

 there is a curved groove in which the loose pterygoids rest. The lat- 

 ter are small, irregularly falcate in shape, and completely detached 

 both from sphenoids and palatines, as in monotrematous orders. The 

 superior maxillaries are fused along the median palatal line, but else- 

 where distinct from each other: and they form the apex of the jaw 

 to the exclusion of intermaxillaries. Their palatal plates are their 

 most perfectly ossified parts ; for the rest, they are made up in great- 

 est part of large alveolar cavities, filled with the future molars and 

 premolars, the walls of which cavities, everywhere thin and fragile, 

 almost spongy, are defective, particularly along the line where they 

 should properly join the palatal plate, displaying the contained 

 teeth through extensive vacuities. The inflated walls of these cavi- 

 ties form the only osseous floor of the orbits ; they project like bullae 

 upward and backward toward the alisphenoids, from which, however, 

 they are entirely separated by a continuous deep and wide fissure. 

 The teeth that have cut the gum have been already noticed ; the lat- 

 eral pair are presumably canine from their relation to the superior 

 maxillary, but occupy the place of incisors. The apex of the upper 

 jaw is defective, and presents a depression between these two lateral 

 teeth, occupied, in the recent state, by a cartilaginous mass, in which 

 the median incisor was buried. The upper, surface of the maxil- 

 laries offers a deej) transverse depression, into which open the large 

 foramina for transmission of the second division of the trigeminus ; 

 posteriority it rises up to meet the under surface of the malars and 

 be articulated with them, in a nearly straight and horizontal line 

 from side to side. 



