352 ON A SPINAL COLUMN OF LOXOMMA ALLMANNI. 



13 ft. 8|-in. So that with these allowances, which appear 

 reasonable, this specimen of Loxomma when living may have 

 been about fourteen feet in length. Its bulk we can only con- 

 jecture; it may have been that of an adult crocodile or alligator. 

 All the vertebral bodies are longitudinally grooved, and have 

 concave anterior and posterior surfaces. 



As to the vertebrae marked Nos. 1, 2, and 3 on the specimen 

 at the cephalic end, it is doubtful whether they are posterior 

 cervical or anterior dorsal. Their bodies are somewhat smaller 

 than those which follow, and rather distorted. Each has on its 

 left side a small, ovoid, concave facet, for articulation with the 

 head of a rib. It is therefore presumable that they are dorsal 

 centres. If they are not dorsal, then the animal had been fur- 

 nished with cervical ribs. Those marked I^os. 2 and 3 are much 

 alike, but gradually and slightly decrease in size backwards. 

 The 4th, 5th, and 6th resemble each other, and with the 7th 

 are somewhat fragmentary. 



Each of the vertebrae marked IS'os. 4, 5, 6, 7, exhibits on its 

 left side a distinct process standing out, having a terminal, con- 

 cave, ovoid surface, for articulating with the head of a rib. 

 Two short fragments of ribs lie over the vertebrae JN^os. 4 and 5. 

 Three of the above four vertebrae have each a broad, flat, smooth, 

 square, well-defined, neural spinous process, beyond which, in 

 the matrix, are the broken-off articular heads of two ribs; on one 

 of which is imbedded the slender bright tooth of MegalichtJiys 

 before mentioned. The zygapophyses of these vertebrae, which 

 adjoin each other, have in three instances retained their normal 

 juxtaposition. Erom these processes to the tops of the neural 

 spines there is a length of one inch and five-eighths. The width 

 of these spinous processes at top is a full inch. The best pre- 

 served centres of these four vertebrae measure from anterior to 

 posterior border at the lowest part three-quarters of an inch. 



No. 8 has suffered from pressure, and is indistinct. By its 

 side lies a broken bit of a rib. 



Nos. 9, 10, 11, and 12 are, together with their intervertebral 

 disks, better preserved. Their neural spines are fairly visible, 

 and about the same size as those of Nos. 4, 5, 6, and 7 ; but 



