43o SOFT-FINNED GROUP. 



The gigantic sun-fishes (Orthagoriscus), which are pelagic forms 

 distributed throughout the whole of the temperate and tropical seas, 

 alone represent the third subfamily, and are distinguished by the extremely short 

 and truncated tail, the confluence of all the median fins, and the short and highly 

 compressed body, the dental plates of the jaws being undivided. The skin is 

 either rough or smoothly tesselated, and incapable of distention with air; there 

 are no pelvic fins ; the air-bladder is wanting ; and there is an accessory opercular 

 gill. As in the globe-fishes, there are no pelvic bones in the skeleton, and the 

 vertebral column is remarkable for its extreme shortness, there being only 

 seventeen segments in the whole series, of which seven belong to the tail. In all 

 the members of the suborder the spinal cord is noticeable for its shortness ; but in 

 the sun-fishes this abbreviation has been carried to such an extent that the whole 

 cord is little more than a conical backward appendage of the brain. The creatures 

 considered to be very young sun-fish are utterly unlike the adult form, having 

 an enormous eye, and the head and body armed with a number of large spine-like 

 projections. The caudal fin is not developed till much later than the dorsal and 

 anal, which in the adult are very short, of -.great height, and placed opposite to one 

 another at the hinder end of the body. The common sun-fish (0. mola), which 

 has a rough, finely granulated skin, attains very large dimensions, an example 

 caught off the coast of Dorsetshire in 1846 measuring 7| feet in length. 



Far rarer is the oblong sun-fish (0. tnmcatus), which is, indeed, one of the 

 scarcest objects in museums. It is readily distinguished by its smooth, tesselated 

 skin, and the more elongated form of the body ; the entire length being nearly 

 three times the breadth. An example of this fish, weighing 500 lbs., was taken in 

 Plymouth Sound in the year 1734 Both species appear to feed on small pelagic 

 crustaceans. In a fossil state sun-fishes have been recorded from strata of lower 

 Miocene or upper Eocene age in Belgium. 



The Soft-Finned Fishes, — Suborder Anacanthini. 



This suborder, which includes the important families of the flat-fish and cods, 

 is characterised by the median and pelvic fins being entirely composed of soft 

 jointed rays ; the pelvic fins, if present, being either jugular or thoracic in position ; 

 and the air-bladder, when developed, having no duct communicating with the 

 oesophagus. It should, however, be mentioned, that a fresh-water Australian fish 

 (Gadopsis) forms an exception as regards the structure of its fins, having spines 

 in the anterior portion of both the anal and dorsal. The suborder is divided into 

 two sections, according to whether the head and body are symmetrical or distorted, 

 the first representatives of the former section being 



Family L YCODID^. 



This unimportant family, for which there is no proper English name, 

 includes small littoral fishes much resembling blennies in general appearance, and 

 mostly characteristic of high latitudes, although a few occur within the Tropics. 

 As a family they are characterised by the confluence of the median fins ; by the 



