i 9 4i CATALOGUE OF FISHES OF TORTUGAS 243 



the home in repair, and often a ring of white sand about the threshold indicated 

 that such work had been done. 



When resting, the fish may sometimes be seen "sitting" in the mouth of its 

 burrow. If there has been no cause for alarm, its ventral fins may beat the level 

 of the opening and its whole head exposed. Otherwise it may "sit" lower, with 

 only the snout and eyes exposed. More commonly the fish "float" a foot or more 

 above their retreats, but on the approach of danger they settle down tail first, and 

 in emergency they dart in head foremost. If one fish's shelter is destroyed it 

 usually seeks refuge with another, but such intrusion appears to be unwelcome, 

 and two were rarely seen living amicably together. 



The fish when "floating" feed on drifting plankton. Their food is greatly 

 varied. In the fraction of a cubic centimeter of material taken from the gut of one 

 specimen, W. L. Schmitt recognized the tail of a shrimp zoea, a small hermit 

 crab, two barnacle larvae, several ostracods, a tanaid isopod, an amphipod, a 

 dozen copepods representing several species, and several recently hatched snails. 



Of 12 fish examined, 5 were without and 7 contained a total of 16 metacercariae 

 encysted in the air bladder. H. W. Manter found that these apparently were 

 Stephanostomum sentum, which also occurs, but less abundantly, in the air 

 bladder of the other Tortugas species of Opisthognathus. 



This golden-brown fish is marked with a yellow wash across the front and 

 nape to base of dorsal, along which it continues for half the length of fin; body 

 and fins faintly bluish except as already noted; a blue line between lateral line 

 and dorsal fin; a dark stripe of pupillary width through eye; iris below this line 

 blue, then yellow, and yellow above it. W. H. L. 



The collection contains 22 specimens, 37 to 90 mm. long. The caudal fin is 

 described and figured as truncate in the original description, whereas it is de- 

 cidedly rounded to somewhat pointed in the specimens at hand. 



The fish have faded in preservative to rather light brown, with the ventral 

 surface of the head and abdomen pale. The "blue line" between lateral line and 

 base of dorsal has turned pale in preservative, and is a scaleless strip; dorsal, 

 caudal, and anal fins pale gray, with a bluish to dusky margin on dorsal and 

 anal, most prominent on dorsal; pectorals plain translucent; ventrals white. 



It is difficult to distinguish between divided and undivided rays in the 

 dorsal and anal, because they are enveloped in rather thick skin. For that reason, 

 no doubt, the counts of the fin rays were given in the original description 

 (Jordan and Thompson, Bull. U. S. Bur. Fish., vol. 24, 1904 (1905), p. 252, fig. 4) 

 without making a distinction, the counts being D. 26; A. 18; P. 18. Two of the 

 specimens at hand have, respectively, D. 26, 26; A. 17, 18; P. 18, 18; gill rakers 33. 

 The scales are too small to enumerate accurately, probably about 115. 



Known only from Tortugas, Florida. S. F. H. 



Lonchopisthus micrognathus (Poey) 



This species is rare indeed in collections. It is only moderately rare in the catch 

 of the terns of the Bird Key rookery. It was first found among scraps picked up 



