2 . 2 PAPERS FROM TORTUGAS LABORATORY vol. xxxiv 



fasciatum. The dark spots on the back, however, definitely extend on the base 

 of the dorsal fin, and the one between the 6th and 9th spines is much nearer the 

 base, larger, and more prominent. The dorsal and anal, especially in large ex- 

 amples, are more profusely spotted with white and dusky, the light longitudinal 

 bands on the dorsal are less distinct, and the caudal has distinct dark bars, ex- 

 cept in the smallest specimens, wherein it is plain. 

 West Indies to Florida. S. F. H. 



Opisthognathus whitehurstii (Longley) 



Gnathypops maxillosa Jordan and Evermann (not of Poey), Bull. U. S. Nat. Mus., No. 47, 



pt. 3, 1898, p. 2284, fig. 801. 

 Gnathypops whitehurstii Longley, Carnegie Inst. Wash. Year Book No. 30, 1931, p. 385 — 



Tortugas, Florida (notes, but no description). 

 Opisthognathus whitehurstii Longley and Hildebrand, Carnegie Inst. Wash. Pub. 517, 



1940, p. 262, fig. 19. 



Opisthognathus aurifrons (Jordan and Thompson) 



(Plate 30, figure 1) 



Tortugas is the type locality for this species, and for more than 20 years it was 

 known only from the type specimen. Yet it is rather common. It is a burrower, 

 however, and has a ready mode of escape from the seine or dredge. As a bur- 

 rower, too, its local distribution is determined largely by the nature of the bottom, 

 and as this often meets its requirements only in small areas it is comparatively 

 easy to overlook it entirely. Found in small numbers over the flats between Long, 

 Bush, and Bird keys, and in larger numbers on the gravelly patches between the 

 shore and reef on the west side of Loggerhead Key, and on similar patches west 

 of the grass belt farther up the reef; on the sandy bottom of a deep hole in the 

 Loggerhead reef there were 18 in sight at once, and in another hole, 27. 



The burrows are perhaps 300 to 350 mm. deep. They are enlarged below, the 

 shape of the terminal chamber being fixed largely by the arrangement of the 

 larger bits of dead coral by which it is surrounded. Rarely a fish was found en- 

 gaged in building its retreat. In one instance one had been at work for some time 

 in the bottom of a depression, where it had made a shaft whose depth was greater 

 than the length of its own body. While being watched, again and again it went 

 out several times its own length and brought back in its mouth bits of shell or 

 dead coral. On its return it entered the burrow tail foremost until its mouth was 

 nearly level with the rim, whereupon it laid its burden down, or shifted it until it 

 seemed to rest snugly in place. Sometimes a piece with algae attached was re- 

 jected. The carrying of "stone" was interrupted from time to time by trips to the 

 bottom of the burrow for sand, or sand was brought in the mouth from outside. 

 The sand was deposited outside and against the rising wall until the construction 

 was brought to the level of the surrounding bottom. Finally the burrow was 

 vertical, in diameter a little greater than the builder's body, and "stone-lined," 

 except in its terminal chamber. Even there it was stone-lined, though naturally. 

 The finished work represents a considerable expenditure of labor, and it appears 

 to be occupied for an indefinite period. Some effort is necessary, however, to keep 



