866 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY — IV. 



anal fins. Dorsal and anal fins liigh in front, rapidly decreased back- 

 wards; caudal fin low, and with a wavy outline. Depth always more 

 than half length, and in the young tbe vertical diameter exceeding the 

 longitudinal. Form varying much with age, the body becoming more 

 elongate, the fins comparatively shorter, the eye much smaller, and a 

 hump being developed above the mouth, topped by an osseous tubercle. 

 Head 3; depth If . D. 17; A. 16. Pelagic, inhabiting most temperate 

 and tropical seas, swimming slowly about near the surface; common 

 northward to Cape Cod and Point Concepcion. It reaches a weight of 

 about 500 pounds. 



(Tetrodon viola Linn. Syst. Nat.: Orthagoriscus mola Bloch & Schneider, 1801, 510: 

 Orthagoriscus mola Storer, Fish. Mass. 420: Orthagoriscm analis Ayres, Proc. Cal. 

 Acad. Nat. Sci. ii, 31, f. 54: "Mola rotunda Cuvier, 1800,") 



