212 PEEP-SEA FTStlES OF I'llE ATLANTIC BASIN. 



are much confused, broken, and split down to the base, aud it is fortunate that Vaillant 

 has been able to make out the true ray formula to be 1, 5. The spine is enlarged into a thin 

 scalpel shaped lamella and marked with numerous obli(iue stria'. 



Giinther concluded, Irom the stru(^ture of the cranial bones, the immense eyes, the 

 black color of the cavity of the moutii and pharynx, and also from the extreme scarcity of 

 the tish, that tliis species belougs to the deep sea fauna, and subsequent explorations proved 

 the wisdom of his prophecy. 



Radial fonuula: 1). 27; A. 23-25; P. 18; V. I, 5. 



Giinther remarks concerning D. aureus, Campbell : 



I should be inclined to refer this fish, which is known from four specimens, 2f inches 

 long, cast up on Hokitika beach (New Zealand), to the sanu; species as the Madeiran speci- 

 men, but for the seeming absence of the enlarged ventral spine. This, of course, might be 

 also accounted for by the less advanced age of the specimens. All the other ditterences as 

 they appear in the description would probably disapi)ear on a direct comparison of the ex- 

 amples. The perforations of the iuterradial membrane of the dorsal and anal fins, which 

 Campbell regards as an extraordinary character, may also be seen in the Madeiran type, and 

 are due to the extremely delicate structure of the membrane. The radial formula is D. 26; 



A. 21 ; P. 17, 



Family PTERACLIDID^E. 



PteracUnw, Swainson, Nat. Hist. Fishes, etc., 1839, il, 178. 

 Vteraclididai, (jiii.L, Arr. Families Fishes, 1872, 9 (No. 85). 



Scombroids with oblong or short elevated body, compressed, covered with moderate 

 sized scales. Dorsal and anal high, composed of simple spines or rays. Ventrals jugular. 



PTERACLIS, Gronovius. 



rteraclis, Gronovius, Act. Helvet., vii, 44, 1772 (type, Corijphrna rdifera, Pallas). — CuviEn and Valen- 

 ciennes, Hist. Nat. Poiss., ix, 359. — Guntuer, Cat. Fish. Brit. Mus., ii, 2, p. 410. — Jordan and Gilbert, 

 Bull. XVI, U. S. Nat. Mus., 455. 



Body compressed, oblong, covered with moderate-sized scales. Snout obtuse convex, 

 comjiressed. Cleft of mouth wide, oblique. Eye large. Dorsal very elongate, much ele- 

 vated, extending from the forehead to the caudal, composed of filiform si^ines, unarticu- 

 lated, triangular in form ; anal similar in form aud structiu-e; ventrals jugular, of 4-6 slender 

 rays. Pseudobrauchiit; present. Air-bladder very small. 



This is a pelagic form, widely distributed, and but sparsely represented in museums. 

 The characters by which the four recognized species are separated are not of the greatest 

 diagnostic importance. 



Pteraclis pajriUo, Lowe, was described in 1843 (Proc. Zoiil. Soc., 1843, p. 83), from 

 Madeira. It has 41 rays in the dorsal, and 35 in the anal. Lowe believed that the last six 

 rays of the dorsal were detached from the rest. 



Pteraclis oeellatus, C. & V. (Hist. Nat. Poiss., ix, p. 363, pi. CCLXXI) was described 

 from Mozambique material. It has a few more rays in the vertical fins (D. 45; A. 42). 



Pteraclis carol iitus, C. & V., was described from a mutilated specimen, 4 inches long, 

 from the coast of South Carolina. 



Pteraclis velifcr, the Coryphccna vclifera of Pallas, came from the Indian Ocean. Liitken 

 has seen fit to identify with it several young individuals 7 to 15 millimeters long, taken with 

 dredge by Andrea and Joersen in the Atlantic, lat. 21° 29' N., long. 28° 36' W. (Spolia 

 Atlantica, 502 and (iOO, pi. iv, fig. B). 



The single specimen obtained by the Albatross agrees sufficiently weU with the descrip- 

 tion of P. carolinus and is assigned to that species for the present. 



PTERACLIS CAROLINUS, Cuvier and Valenciennes. (Figure 218.) 



Pteraclis carolinus, CuviER and Valenciennes, lli.st. Nat. Poiss., ix, 1833. 368.— Gi-nther, Cat. Fish. Brit. 

 Mus., II, p. 411.— .Jordan and Gilbert, Bull, xvi, V. S. Nat. Mus., p. 4.55. 



A Pteraclis with smaller mouth and larger scales tlian P. oeellatus, or P. trichypt-'rus, 

 and with the fourth dorsal very perceptibly longer. (C. tt V.) 



