212 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



are much confused, broken, and split down to the base, and 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 oblique stria?. 



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. 



Eadial formula: D. 27; A. 22-25; 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, 2J inches 

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

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

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

 they appear in the description would probably disappear 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 due to the extremely delicate structure of the membrane. The radial formula is D. 20; 

 A. 21; P. 17. 



Family PTERACLIDIDyE. 



PteracliiuE, Swainson, Nat. Hist. Fishes, etc., 1839, n, 178. 

 Pteraolidida, Gill, 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. 



Pteraclis, Groxovius, Act. Helvet., vn. II. 1772 (type, Coryphcena velifera, Pallas). — Cuvikr and Valen- 

 ciennes, Hist. Nat. Poiss., ix, 359. — GOntheb, Cat. Fish. Brit. Mas., n, 2, j>. 410. — Jordan and Gilbert, 

 Bull, xvi, V. 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, unarticu- 

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

 rays. Pseudobranchite 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 papilio, Lowe, was described in 1813 (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. 



Pteraclis oeellattts, C. & V. (Hist. Nat. Poiss., IX, p. 363, pi. cclxxi) was described 

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



Pteraclis carolinus, ('. & V., was described from a mutilated specimen, 4 inches long, 

 from the coast of South Carolina. 



Pteraclis velifer, the Coryphcena velifera 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. carolinus and is assigned to that species for the present. 



PTERACLIS CAEOLINUS, Cuvif.R and VALENCIENNES. (Figure 218.) 



Pteraclis carolinus, Cuvier and Valenciennes, Hist. Nat. Poiss., ix, 1833, 368. — Gi nther, Cat. Fish. Brit. 

 Mus., li, p. 411. — Jordan and Gilbert, Bull, xvi, IT. S. Nat. Mus., p. 455. 



A Pteraclis with smaller mouth and larger scales than P. ocellatus, or P. trichypt^rus, 

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



