65 



November 5, 1845. 



The President in the Chair. 



A communication from Prof. Jeffries Wyman, on the sub- 

 ject of the fossil skeleton recently exhibited in New York as 

 that of a sea-serpent under the name of Hydrarchos Silli- 

 mani, was read. 



Prof. Wyman stated that, during a recent visit to New York, 

 he had an opportunity of examining the fossil remains exhibited 

 in Broadway under the name of Hydrarchos Sillimani, and pur- 

 porting to be those of an extinct marine serpent. These remains 

 consist of a head and vertebral column, measuring in all 114 feet, 

 of a few ribs attached to the thoracic portion of the latter, and 

 of parts of supposed paddles. 



I. The head. This is five feet seven inches long, or one twenti- 

 eth of the entire length of the whole animal. That part purport- 

 ing to be the cranium proper, and which serves more especially 

 to protect the brain, consists apparently of a single bone, and is 

 destitute of any visible sutures, is a little more than one foot long, 

 about five inches wide, and has, attached laterally by cement, 

 two bones forming incomplete zygomatic arches. Inferiorly it is 

 so much covered with cement that little or nothing can be seen 

 of its surface. Posteriorly there are no condyles, nor any fora- 

 men for the passage of the spinal marrow ; in fact, no foramina 

 are anywhere visible. This absence of sutures and foramina 

 naturally leads to the supposition that it is not the true cranium, 

 but may be some bone or fragment not in its natural position. 

 The size of the supposed cranium is obviously too small for 

 lodging the brain of an animal 114 feet long, inasmuch as its 

 cavity, if it had one, could exceed but little that of the spinal 

 canal which is visible in some of the vertebrae. The upper jaw 

 is narrow and elongated, so that the whole head, with its broad 

 zygomatic arches, has something of the general outline of that of 

 an Ichthyosaurus. The jaw has been crushed by violence, as is 

 obvious from the broken edges of the pieces ; and, in one instance 

 at least, a fragment, containing a tooth, is in an inverted position. 



PROCEEDINGS B. S. N. II. 9 NOV. 1845. 



