VOL. XLVI.] PHILOSOPHICAL TRANSACTIONS. 65Q 



These webs are cartilaginous and fleshy, and are supported by strong bones, 

 analogous to the humeral bones of some other animals. Under each of these 

 is a sacculus or marsupium, which runs up the side of his head, 28 inches deep, 

 and 6 inches wide; these have not been duly taken notice of, except perhaps by 

 Bellonius, who mentions two holes, without adding any thing else about them. 

 But they are of so singular a nature, that there is some encouragement to make 

 the following conjecture. 



The branchial holes are 3 on each side, which are situated deep in the mouth, 

 and open into these marsupia, the sides of which are the branchiostegae, having 

 several long slender cartilaginous bones running longitudinally for their support, 

 analogous to the branchiostegal bones of other fishes; so that probably these 

 sacks may answer two ends ; first, to form the membranae branchiostegas ; and, 

 secondly, to make a convenient receptacle for the young, till they §re able to 

 shift for themselves. Perhaps the following conjectures may serve to strengthen 

 this opinion ; for if this end was not to be answered, the branchiae might have 

 been terminated near their origin in the mouth, as it is in other fishes. 



Authors have ranked this fish among the cartilaginous tribe, who are said to 

 be viviparous; but of this there are disputes among them as yet undetermined. 

 Now if this fish does not bring forth its young perfect, there can be no use 

 assigned to these sacks; for eggs are deposited by the oviparous tribe in sand, 

 weeds, or any other proper nidus; nor could the creatures by any means place 

 eggs in them, because they open in a wrong direction for such a purpose. But 

 if they are viviparous, then the young may probably be harboureii in them, 

 being capable of crawling into them, as we may see by the pectoral webs on the 

 under side. 



And to strengthen this conjecture, we may draw another consideration from 

 the manner of their feeding; for these are creatures of no swift motion, but 

 crawl on the bottoms of shoal places, watching and alluring their prey; now 

 their young cannot be supposed to have power or sagacity enough for this work, 

 till they are grown large and strong, and have these twigs in perfection ; there- 

 fore they must of necessity be protected by the parent, till they are able to pro- 

 vide for themselves, which probably may be when they grow too large to enter 

 into these marsupia. 



There are 7 small finny webs, like little indented leaves, on each side the under 

 jaw, and others of the same kind all round the sides to the tail. He has a dorsal 

 fin near the tail on the spine, and a ventral fleshy fin nearer the tail than the 

 former. The five-fingered webs under the thorax are rough and fleshy, showing 

 their business is to assist in slowly crawling from place to place; and there ap- 

 pears the vestige of the spine from the place of the vent to the tail on the most 

 posterior part of the belly. 



4 p 2 



