i 9 4i CATALOGUE OF FISHES OF TORTUGAS j^j 



increasing in length with age) ; interorbital 3.8 to 4.0; pectoral 1.35 to 1 .45; longest 

 anal spine 1.4. Scales difficult to count accurately, about 40 to 44 oblique rows 

 along middle of side. The number given for the type in the original description 

 is 36, but if oblique rows are counted about 40 may be seen. The anal and pec- 

 toral rays cannot be counted accurately in the type, but the dorsal definitely has 

 XIII, 18, though the original description gave XII, 18. The anal formula was given 

 as III,i7, which comes within the range of Tortugas specimens. 

 Gulf of Mexico, apparently not entering shallow shore waters. S. F. H. 



Pomacanthus arcuatus (Linnaeus). Black angelfish 



Chaetodon arcuatus Linnaeus, Syst. nat., 10th ed., 1758, p. 273 — "India." Poey, Repertorio, 



vol. 2, 1868, p. 351. 

 Chaetodon paru Bloch, Naturgesch. ausland. Fische, vol. 3, 1787, p. 57, pi. 197, fig. 1 — 



Brazil. 

 Chaetodon lutescens Bonnaterre, Tab. encyc, Ichth., vol. 6, 1788, p. 82 — Jamaica. 

 Pomacanthus cingulatus Cuvier and Valenciennes, Hist. nat. poiss., vol. 7, 1831, p. 209, 



pi. 185 — West Indies. 

 Pomacanthus quinquecinctus Cuvier and Valenciennes, ibid., p. 210 — West Indies. 

 Chaetodon littoricola Poey, Repertorio, vol. 2, 1868, p. 351 — Cuba. 

 Pomacanthus arcuatus Longley, Carnegie Inst. Wash. Year Book No. 34, 1935, p. 283. 



The synonymy given was indicated by Dr. Longley (see last reference above). 

 To this may be added virtually all references to Pomacanthus para in recent 

 books. Dr. Longley's reason for using arcuatus instead of paru, a name long 

 accepted, is stated in the first paragraphs of his discussion of P. aureus. 



Nothing on this species was found among Dr. Longley's manuscripts, and I 

 strongly suspect that part of the discussions pertaining to this genus, and perhaps 

 family, has been lost. 



If it is correct to assume that Dr. Longley always listed this species in his field 

 notes under P. paru, then observations and records of capture are limited to eight 

 instances. It is reported from an old wreck, from oflf beach rocks, from Bird Key 

 reef, from among coral heads, and from a channel oflf Bird Key reef. The num- 

 ber of individuals seen evidently was not great, and that it is less common than 

 P. aureus is stated in the discussion of that species. 



The color pattern is not fully described in Dr. Longley's field notes. It is stated 

 only that the young have dark crossbars separated by "narrow yellow lines." In 

 published accounts the "yellow lines" generally are called bars and the dark be- 

 tween them the ground color. In any event the yellow bars are lost with age, and 

 the fish become almost black, except for yellow margins on some of the scales. 



This species, as understood by Longley, is distinguished by the convex caudal 

 fin and its rather rounded lobes, in contrast with a straight or slightly concave 

 margin with angulate lobes in aureus. Furthermore, arcuatus generally has 10 

 spines in the dorsal, whereas aureus usually has only 9. A rather convenient dif- 

 ference in separating preserved adults is the very narrow white margin of the 

 caudal fin in arcuatus, in contrast with the rather broad one in aureus. Minor 

 differences in the color of the young are pointed out under aureus. 



Atlantic coast of tropical America, northward to Florida. S. F. H. 



