104 



MOTELLA. 



The defiuition of this genus by Cuvier is, — the anterior dorsal fin 

 so low as to bo scarcely perceptible, which, standing alone, is at least 

 as applicable to the very different genus Raniceps as to this. But the 

 organ often represented as the first dorsal fin, in this genus has no 

 nearer title to the name of a fin than what arises from its situation 

 at the anterior portion of the back, where its seat is in a chink, 

 from whence it projects when the fish is in the water, but it lies 

 almost hidden when the fish is dead. It does not possess rays, as do 

 all tlie true fins of these fishes; but it is formed of membrane, from 

 the edge of which rises a thickly placed row of threads, the foremost 

 of which is the stoutest and most prominent. When these fishes are 

 alive in their native element, and resting, as they familiarly do, on 

 the ground, with all their true fins at rest, this organ is in continued 

 and rapid action; and its intimate structure shews that while it is 

 destitute of any power of propulsion, or of regulating motion, it is 

 well furnished with nerves which render it acutely sensible to impressions. 

 This dorsal membrane is in fact supplied with a special nerve, which 

 reaches it directly from the brain, and which also passes onward to 

 the true dorsal fin. A bi'anch of this nerve also goes to the pectoral 

 and ventral fins, Avhich are thus endued with particular powers of 

 sensation, in addition to those of action, the last-named faculty being 

 influenced into energy by branches of the intex'costal nerves. The 

 facial nerve also divides into four branches, one of which passes to 

 the back of the head and upper portion of the outside of the orbit ; 

 a second branch passes through the lower portion of the orbit, and 

 also supplies the director muscles of the eye itself, whilst the other 

 two are distributed to what may be spoken of as the face. These 

 observations have been obtained from examination of the Three-bearded 

 Eockling, Motella vulgaris or tricirrata, but it is probable that they are 

 equally applicable to the other species of this familj^; and they tend 

 to shew the exquisite provision which is made for the supply of organic 

 sensibility to a family of small fishes, the lives of which are for the 

 most part passed in places where feeling is more important even than 

 sight, as well for their safety as subsistence. The essential character 

 of the genus Motella is, that with the other portions of structure of 

 the gadoid family, they possess barbs on the upper and lower jaws, 

 together with a ciliated membrane, which is seated in a chink between 

 the head and dorsal fin. 



