DISCUSSION OF SPECIES AND THEIR DISTKIBUTION. 209 



Body compressed and elongate. Teeth on jaxrs, vomer, and palatines. Skull -witli 

 crest. A single, elongate dorsal; anal shorter; pectoral very small; ventrals thoracic. 

 Lateral line present. Gill membranes free from isthmus. Branchiostegals 7. No pscudo- 

 branchiiB. No air bladder. Pyloric appendages numerous. Vertebru; more than 10+14. 



CORYPH^^NA, Linneeus. 



Coriipha'na, Linn.eus, Syst. Nat., ed. x, 1758, I, 261. — Cuvier and Valenciennes, Hist. Nat. Poiss., ix, 



268. — GuNTHER, Cat. Fish. Brit. Mus., li, 404. — Jordan aud Gilbert, loc HI. 

 Lampitgus, Conner and Valencienxe.s, op. cit., 317. — Gill, Proc. Acad. Nat. Sci., Phila., 1802, 127. 



Body elongate, covered with small, cycloid scales. Cleft of tlu; mouth )blique, the 

 lower jaw projecting. Cardiform teeth on jaws and vomer and palatines ; a patch of villiform 

 teeth on the tongue. Skull-crest much more elevated in adult than iii young. Dorsal 

 many-rayed, low, extending from nape nearly to base of catidal; anal similar, but shorter; 

 both without distinct spines; pectorals small ; ventrals well developed, thoracic, 1, 5, partly 

 received into a groove in the abdomen; caudal tin widely forked. 



Liitkeu lias reviewed iu his Spolia Atlantica the species of the genus Corypluvna, aud an 

 abstract of his conclusions is here presented: 



The genus CorypJta'na, the "Dolphins" as they are called Ijy sailors, is one of those 

 peculiarly pelagic in its characteristics, and it is an example, more remarkable than any 

 other, of the extreme confusion which has resulted from the fact that a numbe. of really 

 limited existing species has been divided into a great number of nominal species, based 

 only upon differences of age and sex, individual peculiarities, difi'erent geographical locali- 

 ties, carelessly made drawings, incomplete descriptions, etc., a confusion which has been 

 wrongly charged to Ouvier. The mistake of separating the species into two genera, Cory- 

 phwna and Lampugus, has already been rectitied by competent authority, and the number 

 of species believed to be well founded at the same time was reduced from 19 to G. He is now 

 of the opinion that the number siiould not be more than 2, or at the most 3. The two time- 

 honored species of Liun;eus, the large Dolphin, "La Petite Dorrade" (C. hippurus), which 

 reaches a length of nearly 6 feet; and the little Dolphin, " La Petite Dorrade" (V. cquisefls), 

 which rarely exceeds 2^ feet. In Spolia Atlantica, Liitken gives an extensive comparison 

 of these two species, having special reference to the changes which they undergo with age, 

 and those which, like the length of C. cquiscfis, are sexual ; aud these variations have been illus- 

 trated by figures of the head, which are reproduced in this work. Most of the species de- 

 scribed and figured can, according to Liitken, be very easily assigned to the two cosmopoli- 

 tan species referred to, which have been often brought in by sailors, the only ones, in fact, 

 from which he has been able to get material for study. Liitken hesitates in his oi)inion 

 concerning G.pelaglca. {azorica, sivuhi) of the Mediterranean, which has been accepted by 

 most authors who have studied the 'Mediterranean fauna, but which very probably does 

 not differ specifically from C. hippurus; at least, he felt obliged to regard as a young speci- 

 men of this species a little " C. peku/icn'^ from the Mediterranean, which, under that name, 

 was sent to him for examination by a museum in Italy. In support of his opinion that 

 there are really only two species of Goryplucna, he mentions two circumstances— one, that 

 Giinther, although he formally acknowledges more, actually refers all the si)ccimens in his 

 own custody to these two species and has not recognized any others; and again, that Liit- 

 ken himself has been able without difliculty to divide numerous s])ccimens of young Cory- 

 phwna, from 18 to 62 millimeters long, caught by Scandinavian Oshennen, into two series, 

 representing two species, and to refer tliese series to the two species before mentioned, and 

 to no others, to wit, most of them to C. equi.scHs, and a fewer number to C. hippurus. The 

 little Coryphamas are so dissimilar to the adults that it is very ea.sy that they should have 

 given rise to mistake, and thus it has happened that the young C. hippurus has been de- 

 scribed by Pallas under the name of C.fnsciolata. Liitken, in the work referred to, gives 

 comparative descriptions of the young individuals of both species in their successive states 

 and in relation to their adult fornLS, and gives figures illustrative of his ideas, calling at- 

 tention to the fact that the greater length of the ventrals iu C. hippurus, and their jioint of 

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