336 DR. A. (it ; NTHER ON AUSONIA CUVIERI. [June 12, 



3. Remarks on the Skeleton of Ausonia ciwieri. 

 By Albert Gunther, M.A., M.D., Ph.D., F.Z.S. 



Several vears ago, when on a visit at Frankfort to examine typical 

 specimens of the Senckenbergian Museum, my attention was directed 

 to a skeleton of Ausonia cuvieri, perhaps the only osteological ex- 

 ample of this fish existing in a Museum of Natural History, for 

 which, as for most of its zoological treasures, Frankfort is indebted 

 to the indefatigable zeal of Riippell. Not only did Dr. Riippell allow 

 me to make notes from the specimen, but gave me, besides, a drawing 

 of the skeleton, which is reproduced in the accompanying woodcut, 

 and his notes on the splanchnology. The latter, however, do not 

 contain anything not previously observed in Nardo's memoir " De 

 Proctostego." 



As I am not aware that any notice of the osteology of this unex- 

 pected visitor to the British seas has been published, I think it right 

 not to pass by this occasion of appending my notes to the preceding 

 paper of Mr. Couch. 



I infer, from the feeble development of the whole osseous structure, 

 and particularly from the relatively small quantity of inorganic sub- 

 stance, that Ausonia is a deep-sea fish, inhabiting not that deeper 

 zone in which Plagyodus (Steller, =■ Alepidosaurus, Lowe) and other 

 carnivorous fishes live, and where a vegetable-eater, such as Auso- 

 nia evidently is, could not subsist, but a zone at a depth of perhaps 

 a hundred fathoms, perhaps in company with Centrolophus and 

 Pomatomus* . 



The configuration of the bones of the skull will be seen from the 

 accompanying figure. The prefrontal is elongate, straight, extend- 

 ing from the upper margin of the orbit to the extremity of the snout, 

 where it terminates in a slight swelling which is the union with that 

 of the other side. The fronto-parietal crest is subtriangular, and 

 commences immediately behind that swelling ; it is slightly thick- 

 ened. Maxillary extremely feeble. Vertebrae 11/11. The first 

 intemeural spine is very strong, much longer and stronger than the 

 others (which are thin and styliform), flat, sabre-shaped, and de- 

 scends to above the occipital foramen, in front of the first neural 

 spine, which is still stronger than the bone just described. The 

 second neural spine has a broad basal portion which passes abruptly 

 into the upper thin and styliform portion. One intemeural gene- 

 rally corresponds to a neural. All the interneurals are so much 

 dilated above that their upper extremities appear to be united by 

 one semiossified ligament, which extends from the parietal crest to 

 the end of the dorsal. The first rib is attached to the third verte- 

 bra, the tenth vertebra is without rib ; all the ribs are anchylosed 

 with the* centra of the vertebrae, opposite to the base of the neural 

 spines. The haemal of the eleventh vertebra is extremely long and 

 slender, arched forward, and passing into a semiossified ligament 



* Dr. Riippell has also presented to the Senckenbergian Museum a skeleton of 

 Pomatomus telescopium ; it has 13 13 vertebrae. 



