FISHES. 375 



I have ventured to name this genus in honour of Sir 

 EvERARD Home, who has so successfully investigated the 

 aerating and reproductive organs of the tribe to which it 

 belongs, and who has pointed out its distinguishing inter- 

 nal characters *. The trivial name is due to the late illus- 

 trious Banks, by whom the species was brought to this 

 country from the South Seas. H. Banksii. 



(2.) Maxillary ring without teeth. 



3. Ammocetes. Lip semicircular. A. branchialis. 



B. Two branchial apertures on each side, and internally 

 only six cavities. 



4. Myxine. This is the Gasterobranchus of Block. 

 M. glutinosa. The Gasterobranchus Dombey of Lace- 

 pede, is probably a Homea. 



2d Tribe. 



Lips unfit to act as a sucker. 



This tribe comprehends the old genera Chimasra, Squa- 

 lus, and Raia. The palatine and post-mandibular bones 

 form the jaw, for the support of the teeth. Tliisjaw is either 



" " In an animal brought from the South Seas by Sir Joseph Bankb, 

 intermediate between the lamprey and myxine, but differing so much from 

 both, as to form a distinct genus, the respiratory organs resemble those of 

 the lamprey in the number of the external openings, and the number of 

 bags ; but these organs, and many other parts, differ in the following parti- 

 culars, in which they agree with those of the myxine. There is no appear- 

 ance, whatever, of thorax, nor is the pericardium cartilaginous ; the bags 

 are flattened spheres placed perpendicularly, their cavities are small, their 

 coats elastic, and the internal orifices communicate directly with the oesopha- 

 gus, which is small. The oesophagus does not terminate in a valvular slit, 

 but in a loose membranous fold ; there are two rows of teeth on each side 

 of the tongue, bent downwards, long, and pointed. There is a posterior 

 nostril, and an appearance resembling an uvula. There is a gall bladder, a 

 row of large mucous glands on each side of the belly, and there is a mesen- 

 tery to the intestine." Phil. Trans. 1815, p. 258, tab. xii. f. 1. 



