Jordan and Evomann. — Fishes of North America. 1753 



686. MOLA, Cuvier. 

 (Head-fishes.) 



J/ote, CtJviEE, Tableau t\km. Hist. Xat. Animaux, 323, 1798 (rotunda— mola). 

 Orthmgorisms, Bloch, Syst. Ichth., Schneider Ed., 510, 1801 (mola) ; misprint for Orthago- 



riscttt. 

 Cephalut, Shaw, General Zoology, v, 2, 432, 1804 {mola). 

 Orthiagus, Eakinesque, Caratt. Ale. Kuov. Gen. e Nuov. Sp. Anim. e Piante della Sicilia, 17, 



U\Q{luna=mola). 

 Diplanchias, Rafinesque, Caratt. Ale. If uov. Gen. e Kuov. Sp. Aniiu. e Piante clella Sicilia, 



17, 1810 (nasus — mola). 

 Tumpanomium, Eanzani, Novi Comm. Ac. Sci. Bonon., v, 3, pi. after p. 81, 1837 (planci= 



mola). 

 Trematopsis, Kanzani, Novi Comm. Ac. Sci. Bonon., v, 3, pi. after p. 81, 1837 (willughbeii = 



mola), 

 Ozodura, Eanzani, Novi Comm. Ac. Sci. Bonon., v, 3, pi. after p. 81, 1837 (or»ini — mola). 

 Pedalion (GuildingMS.) Swainson, Nat. Hist, and Class'n Fishes, etc., v, 1, 199; v, 2, 195 



329,1839. ' ' • 



Aledon, Castelnau, Mem. sur Poissons Afrique Aust., 75, .^1860 {storeri = mola). 

 Lakv'al Forms. 



Molacanthus, Swainson, Nat. Hist, and Class'n Fishes, etc., v, 2, 195, 329, 1839 (pallasi). 

 Pallasia, Nardo, Ann. Sci. Eegno Lombard., Venet., v, 10, 112, 1840 (pallasi). 

 Acanthosoma, De Kay, New York Fauna: Fishes, 330, 1842 (carinatum). 

 Cenlaurus, Kaup, Archiv. Naturgesch. 1855, i, 221 (hoops). 



Body ovate, strongly comi)ressed, covered with a thick, rough, leathery, 

 elastic skiu, which is without bony plates. Profile forming a projecting 

 fleshy nose above the mouth. Dorsal fin beginning not far behind pecto- 

 rals, short and high, falcate, confluent with the anal around the tail; no 

 large spines on the body. Clumsy fishes, found in most warm seas, reach- 

 ing a great size ; the young (Molacanlhus) ^ with the body deeper, much com- 

 pressed, without trace of caudal fin, its place taken by a row of marginal 

 spines, {mola, a millstone.) 



2172. MOLA MOLA (Linn.-ens,. 



(Su.NFi.SH; Head-fish ; Mola; Pez Luna.) 



Head 3; depth Tf. D. 17; A. 16. Dorsal and anal fins high in front, 



rapidly decreasing backward, the height of each about 2^ in length of 



body in adult ; caudal fin low, with a wa,vy outline. Depth always more 



*The nominal genus Jirolaca7itJms, Swainson (Pallasia, J^ardo; Acanthosoma De Kay) 

 has thus been dehned: Body suborbicular, much compressed, deeper than long covered 

 by a thm silvery skin on which are many strong spines. Dorsal and anal fins high and 

 short, not confluent, the space on the tail between them occupied by a row of small spines ■ 

 no mterspinal bones for the support of the caudal ; pectorals moderate. Intestines short' 

 with but 2 turns. These small fishes were long generally considered as the young of 

 J/oia.l he researches of Prof. Frederick Ward Putnam (Am. Nat., Dec, 1870) seemed to 

 show that they were adult fishes aUied to Mola, careful comparisons having been made by 

 hini between Molacanthus and the young of 2Ma. In a specially valuable paper ' ■ On the 

 origin ot heterocercy and the evolution of tlie fins and flu rays of fishes " (Eept. r. S. Fish 

 Comm. tor 1884), the late Prof. John A. Ryder, of the University of Pennsylvania, has 

 careful y discussed the relations of Molacanlhus to Mola. The researclies of Professor 

 Kyder leave no doubt that Molacanthus is simply a post-larval pliase in the deveh)pmeut 

 ot Mola, as was supposed by Liitken, Steenstrup, and Giintber. According to Rvder, the 

 <'^.': if^'-^iorm.s of Mola (corresponding to the form called Ostracion boops by Eichardson) 

 will bo found to have a distinct tail. 

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