344 GILPIN — ON OKTHAGOIliyCUS MOLA. 



lateral line. The dorsal and anal fins both had rays in faint 

 longitudinal marks. The part of the body behind the fins tapered 

 gradually away, the upper half was divided into four irregular 

 lobes, the lower part too irregular a line to classify, and contained 

 a sharp point near the bottom. I could not detect anything ap- 

 proaching to fin rays edging what may be called the tail, except 

 that the tubercles or granulations covering the whole body were 

 laro:er and more numerous on the free edo-e. 



Gunther speaks of a spine or horn on the forehead, this was 

 wanting, though there w^as an approximation to it in a sharp pro- 

 tuberance. His spine in the tail was also only a sharp place. A 

 taint brownish Wash on the breast was the only approach to Couch's 

 colouring, nor was there that decided black band around the tail as 

 described and figured by Dr. DeKay. These probably are the 

 markings of the young. I was unable to disect the whole fish from 

 its putrid state. The liver was very large, pale yellow, and oily ; 

 the intestines simple and short, and the whole body of the fish 

 formed by an oily cartilagenous substance about two inches thick on 

 the belly, three or more on the back. The skin was intimately 

 joined to this, as not to be separated by a knife ; but pieces cut out 

 and exposed to the air, slowly dissolved in oil, leaving the skin 

 entire. This substance was beautifully white, cut with a fine pearly 

 edge, and resembled adipocere. The whole fish was of one un- 

 dulatory elastic mass. The bones as far as I could perceive were 

 cartilagenous and cut easily with a knife. In profile the fish- 

 resembles the single screw propeller used in the serv'ice, and no 

 doubt the motion gained by rotation, is in the fish obtained by the 

 oscillation in opposite directions by both fins, the tail part having 

 motion enou2:h to steer. The fishermen relate accounts of its s^reat 

 velocity when attacked and roused, though usually it it is surprised 

 basking upon its side and sleeping. 



Cuvier informs us that the skeleton of this order of fishes is 

 fibrous, yet its "tardy indurations" to use his own expression — 

 its — all but rudimatary ribs, and absence of suture in the maxillary 

 bones bring it exceedingly near the cartilagenous fish, and causes 

 one to wonder how motion can be transmitted through its unwieldy 

 undulatorv elastic mass. 



