SKULL AND OTHEK BONJES OF LOXOlVCUA ALLMANNI. 219 



colourless, are distinctly observed to cross over the pale band 

 and unite with those of the other side, either as straight tubes, 

 or forming with them a delicate and pale network, resembling 

 that of the granular layer, but devoid of its colour. 



V. The other bones of Loxomma that have been picked up are 

 as follows : — eighteen separate centra of vertebrae, and twenty 

 others imbedded more or less in slabs of shale in company with 

 entire or fragmentary ribs ; twenty -four ribs, of which a good 

 many are nearly perfect, showing the head and tubercle ; and 

 seventeen bones of the extremities, one of which is a humerus, 

 the rest digital, large and small. All these bones are well ossi- 

 fied, and their articular surfaces mostly perfect. 



The centra of the vertebras are commonly of considerable size, 

 alternately larger and smaller, strongly compacted, and have the 

 anterior and posterior surfaces concave, the former being less so 

 than the latter ; several show no facets for the heads of ribs. 



The vertebral canal, where it can be seen, is small. The 

 arches are therefore short, but strong, and unite above in a 

 broad and high, but thin, spinous process ; this is entire in only 

 one specimen, but nearly perfect in two or three others; it 

 stands up straight, inclining neither forward nor backward. All 

 parts of the vertebrae are well ossified. 



The following are the measurements of the vertebra, a dorsal, 

 which is the most perfect, and is figured in Plate III., fig. 4 : — 

 Length of the body eleven-fifteenths of an inch, transverse dia- 

 meter, one inch and five-sixteenths, vertical diameter, one inch 

 and seven-sixteenths ; height of neural arch, five-sixteenths of 

 an inch, height of spinous process two inches, length of same 

 from front to back, one inch and five-sixteenths, thickness, two- 

 sixteenths of an inch. The body is grooved transversely, and 

 has on each side of its upper and lower surfaces a more or less 

 distinct half -facet for a half -head of a rib. The transverse pro- 

 cesses are one inch in length, and have each a concave articular 

 surface on the front of their extremities to receive the tubercle 

 of a rib. The articular processes are sharply defined, their fa- 

 cets nearly circular and fiat ; the anterior pair face upwards and 



