OCT. 1895. VERTEBRAL COLUMN OF AMIA HAY n 



Franque states that the first vertebra, omitting the two which 

 are consolidated with the skull, has no transverse processes, while 

 the next has these, and likewise sometimes bears ribs. In a specimen 

 before me the processes of the first vertebra are certainly not con- 

 spicuous, but they can hardly be said to be absent. They stand out 

 each as a bony ring surrounding a shallow pit, formed by a shrinking 

 of cartilage. In this specimen, too, these processes support a pair 

 of ribs, each of which is as long as the first five vertebrae taken to- 

 gether. Shufeldt could find no ribs on the first vertebra. In 

 another specimen I find no ribs on the first vertebra, but there is a 

 pair on the second. Schmidt figures the first pair of ribs on the 

 third vertebra. In like manner my specimen has ribs on the last dor- 

 sal vertebra, as also did the specimen figured by Schmidt. Neither 

 Franque nor Shufeldt found such ribs in the specimens investigated 

 by them. 



On the upper and lower surfaces of each of the free pleuro- 

 centra of the tail, in a line on each side with the bases of the 

 arches, are found, in fresh specimens, slightly projecting masses of 

 cartilage. Schmidt describes these and gives figures of them viewed 

 externally and in microscopic section. He regards them as rudiment- 

 ary arches, upper and lower, belonging to the intercalated vertebral 

 bodies. Stannius (58, p. 21) refers to these, and compares them to 

 the masses of cartilage which are seen between the true vertebrae 

 and the arches resting on them. But Franque had observed them 

 still earlier, as is shown in the paragraph already quoted from him. 



Schmidt has described another set of cartilages, which, he claims, 

 have not been mentioned by other writers. These are said to be 

 found in front of the bases of the upper arches of the dorsal ver- 

 tebrae, and they fill up partially the space between the successive 

 arches. Schmidt regards these cartilages as homologous with those 

 just described as occurring on the upper side of the " intercalated " 

 bodies of the tail, and therefore as rudimentary upper arches. I will 

 say here that I have examined these masses by means of transverse 

 and longitiidin^.1 sections, and find that they are not distinct carti- 

 lages, but the anterior portions of the masses which occur between 

 the several vertebral bodies and their neural arches. 



There is another system of cartilages which is of much interest, 

 and which has received little attention. These are found on the under 

 side of all the dorsal vertebrae, there being two to each vertebra. On 

 most of the vertebrae these two cartilages project somewhat beyond 

 the surface of the bone in a linear form, and are placed one on each 

 side of the tract occupied by the dorsal aorta. In the dried skeleton they 



