866 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



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

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

 than half length, and in the young the 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 mola Linn. Syst. Nat.: Ortliagoriscus mola Blocb & Schneider, 1801, 510: 

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

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



