212 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



are raucli coufused, broken, and split down to the base, and it is fortunate that Vaillant 

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

 scalpel-shaped lamella and marked with numerous oblique strite. 



Giinther concluded, from the structure of the cranial bones, the immense eyes, the 

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

 the fish, that this species belongs to the deep sea fauna, and subsequent explorations proved 

 the wisdom of his prophecy. 



Radial formula: D. 27; A. 22-25; P. 18; V. I, 5. 



Giinther remarks concerning B. aureus, Campbell : 



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

 long, cast up on llokitika beach (New Zealand), to the same 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 difterences as 

 they appear in the description would probably disajjpear on a direct comparison of the ex- 

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

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

 are (lue to the extremely delicate structure of the membrane. The radial formula is D. 2C>; 

 A. 21; P. 17. 



Family PTERACLIDID^^. 



PteracHiiw, Swainson, Nat. Hist. Fishes, etc., 1839, ii, 178. 

 PteracHdidce, Gill, Ait. 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. Yentrals jugular. 



PTERACLIS, Gronovius. 



PteracUs, Gronovius, Act. Helvet., vii, 44, 1772 (type, Coi-yphcrna velifera, Pallas). — Cuvier and Valen- 

 ciennes, Hist. Nat. Poiss., ix, 359. — Gunther, Cat. Fish. Biit. Mus., ii, 2, p. 410. — .Iordan ami Gilbekt, 

 Bull. x^■I, U. S. Nat. Mus., 455. 



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

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

 vated, extending from the forehead to the caudal, composed of filiform spines, unarticii- 

 lated, triangular in form ; anal similar in form and structure; veutrals jugular, of 4-6 slender 

 rays. Pseudobranchiic 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. 



PteracUs pn})iUo, Lowe, was described in 1843 (Proc. Zool. 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. 



PteracUs oceUatits, 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). 



PteracUs carolinus, C. & V., was described from a mutilated specimen, 4 inches long, 

 from the coast of South Carolina. 



PteracUs veUfcr, the GoriiplicBna veUfera 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 600, pi. iv, fig. B). 



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

 tion of P. caroUnus and is as.signed to that species for the present. 



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



PteracUs carolinus, Cuvier and Valenciennes, Hist. Nat. Poiss., ix, 1833, 368. — Gunther, Cat. Fish. Brit. 

 Mus., II, p. 411. — Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., p. 455. 



A PteracUs with smaller mouth and larger scales than P. oceUatus, or P. trichypt-rui, 

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



