2i6 PAPERS FROM TORTUGAS LABORATORY vol. xxxiv 



shallow banks and at certain other points on the margin of two large, deep holes 

 between Bird Key harbor and the reef to the east. 



About corals I once saw many of these fish lying on the bottom all mottled, 

 matching and blending with their surroundings so well that at least some of 

 them were difficult to see. The mottling, more or less reduced, persisted on some 

 that were swimming off, and on some it was replaced by stripes. The species may 

 appear also in an essential self-color, except for its countershading. The change 

 from one to the other may occur very quickly. Gray, olive, or a brownish cast 

 may prevail in any of the three phases, as one or another is the dominant hue in 

 the environment. In a slate-bottomed aquarium bare at one end, at the other 

 covered with white sand, fish coming to the dividing line repeatedly changed 

 their shade almost as soon as their eyes reached it. In free fish, passing from bare 

 sand to alga -covered bottom, one may see the same adjustment. 



Fish commonly rest in their mottling, but may show it when swimming. They 

 commonly swim in stripes, but are not rarely seen "standing" in stripes in a 

 steeply tilted pose which they often assume, and they even show stripes some- 

 times when resting on the bottom. They may feed in motley, in stripes, in self- 

 color. W. H. L. 



The foregoing was prepared by Dr. Longley. Several marginal notes, however, 

 showed that he did not consider it complete. One note indicated that he thought 

 this species might be Scams aracanga Giinther (Cat. fish. Brit. Mus., vol. 4, 1862, 

 p. 209), a matter he apparently decided as shown by the supposedly later pencil 

 note written over the account, "Call this pachycephalum ," indicating that he had 

 decided this fish definitely needed a name. Accordingly I have inserted the name 

 proposed. (See also first sentence under Scants pitnctulatus , below.) Scar us 

 aracanga was described as having a series of 3 large scales on the cheek. The 

 specimens herein called S. pachycephalum have 5 scales in the single series on the 

 cheek. It seems improbable, therefore, that the two are identical. 



Preserved specimens of S. pachycephalum and S. rubripinne are extremely dif- 

 ficult to separate, and I am not sure that I have succeeded. 



Atlantic coast of tropical America to Florida and sometimes northward. 



S. F. H. 



Scarus punctulatus Cuvier and Valenciennes 



Scarus punctulatus Cuvier and Valenciennes, Hist. nat. poiss., vol. 14, 1839, p. 144 — Mar- 

 tinique. 



Scarus diadema Cuvier and Valenciennes, ibid., p. 146 — Martinique. 



Scarus flavomarginatus Cuvier and Valenciennes, ibid., p. 150 — Martinique. 



Pseudoscarus taeniopterus Giinther (not of Desmarest), Cat. fish. Brit. Mus., vol. 4, 1862, 

 p. 226 — Trinidad. 



Pseudoscarus aracanga Giinther, ibid., p. 227 — Jamaica. 



? Scarus bollmani Jordan and Evermann, Proc. U. S. Nat. Mus., vol. 9, 1886, p. 470 — 

 Tampa, Florida. 



The types of Scarus flavotnarginatus and Pseudoscarus aracanga are thor- 

 oughly representative specimens of S. punctulatus. 



