490 PISCES (OSSEI) GYMNODONTES. [TETRODON. 



DIMENS. Entire length one foot seven inches ; length of the belly, 

 when distended, one foot ; the whole circumference in that situation two 

 feet six inches. PENN. 



DESCRIPT. (Form.) Body usually oblong, but when alarmed the fish 

 has the power of inflating the belly to a globular shape of great size : the 

 whole surface of the abdomen, down to the vent, armed with small sharp 

 spines, each arising from a distinct stellated root of four processes : mouth 

 small : back from head to tail almost straight, or at least very slightly 

 elevated : dorsal placed low on the back ; anal opposite : caudal almost 

 even, divided by an angular projection in the middle : pectorals present ; 

 ventrals wanting. 



D. 11; A. 10; C. 6; P. 14. 



(Colours.) Back of a rich deep blue: belly and sides silvery white; the 

 spines of a rich carmine-colour : tail and fins brown : irides white, tinged 

 with red. PENN. and DON. 



An individual of this species is recorded by Pennant as having been 

 taken at Penzance in Cornwall. A second specimen, also captured on the 

 Cornish coast, is figured by Donovan. Bloch appears to have considered 

 Pennant's fish as his T. lagocephalus *, but by Donovan it was thought, 

 and apparently with some reason, to be distinct. This and all the other 

 species in this genus have the power of inflating the abdomen to a large 

 size, at the same time that they erect the spines with which it is armed, 

 by which means they defend themselves against the attacks of their 

 enemies. 



GEN. 69. ORTHAGORISCUS, Schn. 



179. O. Mola, Schneid. (Short Sun-Fish.) Depth 

 about two-thirds of the length : skin rough. 



O. Mola, Flem. Brit. An. p. 1 75. Mola Salviani, Will Hist. Pise. 

 p. 151. tab. I. 26. Tetrodon Mola, Linn. Syst. 'Nat. torn. i. 

 p. 412. Don. Brit. Fish. vol. n. pi. 25. Dioclon Mola, Block, 

 Ichth, pi. 128. Cephalus brevis, Shaw, Gen. Zool vol. v. part ii. 

 p. 437. pi. 175. Turt. Brit. Faun. p. 116. Sun-Fish, Borl 

 Cornw. p. 267. pi. 26. f, 6. Short Diodon, Penn. Brit. Zool. 

 vol. HI. p. 131. pi. 19. Short Tetrodon, Id. (Edit. 1812.) vol. in. 

 p. 172. pi. 22. 



LENGTH. From three to four feet. 



DESCRIPT. (Form.) Oblong, approaching orbicular, truncated behind : 

 sides very much compressed; the dorsal and ventral lines presenting a 

 sharp edge: depth behind the pectorals about two-thirds of the entire 

 length; thickness rather more than one-third of the depth: head not 

 distinguishable from the trunk; mouth small; jaws exposed; the lamel- 

 lated substance undivided: eyes moderate, about equidistant from the 

 corner of the mouth and the branchial aperture, which last is of an oval 

 form, and situate immediately before the pectoral fin : skin destitute of 

 scales, but every-where very rough with minute granulations : no lateral 

 line : dorsal placed at the further extremity of the body, short but very 

 much elevated, its height equalling two-thirds or more of the depth of 

 the body, terminating upwards in a point ; rays very much branched : 

 anal opposite and exactly similar to the dorsal : caudal with the posterior 



* Ichth. pi. MO. 



