1 94 1 CATALOGUE OF FISHES OF TORTUGAS 267 



On this evidence, including an acquaintance with the habits of the species and 

 some knowledge of the degree of accuracy with which Poey was working, it 

 seems that B. marmoreus and B. stearnsi are identical. 



Although Blennius jucorum has been reported from off New York, from 

 Chesapeake Bay, and from Cooper's River, Charleston, South Carolina, speci- 

 mens are not available for the confirmation of the correctness of the identifica- 

 tions. The type was discovered off the Azores in water from the pumps on a ship 

 homeward bound from South America. That small fishes do make transatlantic 

 passages among weeds and other growth on ships' hulls seems to be proved from 

 specimens of two species of tropical American blennies which J. R. Norman 

 showed me in London, that had been transported in that way to Copenhagen. 

 The type of B. jucorum is a male, 62 mm. long; standard length 53 mm.; depth 

 14 mm.; head 13 mm.; eye 4.0 mm.; preorbital width 2.0 mm.; interorbital width 

 1.0 mm. D. XII, 15; A. 11,17, both fins free from caudal, their longest rays extend- 

 ing about to its base; P. 14, reaching the vertical of 1st anal spine; V. 1,3, extend- 

 ing halfway to anus; anterior nostril with a slight trifid tentacle; ocular tentacle 

 flattened, its base transverse, of the width of the superior opaque envelope of the 

 eye on which it stands, with several minor branches at base, the main axis pre- 

 ponderant, reaching base of 2d dorsal spine. Color of body and fins brownish; 

 dorsal with a dark area on anterior web, and about three rows of dark spots run- 

 ning obliquely down and back; soft dorsal nearly uniformly of the ground color 

 of spinous part; anal unspotted, darker distally; back at dorsal base with about 

 six dusky areas; eight or ten small dark spots along straight part of lateral line, 

 and another series above, halfway between these and dorsal base; several more 

 or less diffuse and irregular rows of spots crossing pectoral. The teeth are fixed 

 and immovable, 26 small ones and a pair of great recurved, noncontinuous 

 canines in upper jaw, and 24 with a similar contiguous pair on lower jaw. Al- 

 though the color pattern is very like that of B. marmoreus, and the vertical fins 

 have only a dorsal and an anal ray less than the least in the small numbers here 

 dealt with, yet until more material is available the identity of B. jucorum and 

 B. marmoreus must be left an open question. 



This fish feeds largely on filamentous algae, and to a lesser extent on a variety 

 of animals including small tunicates, clams, amphipods, bryozoans, bits of 

 sponge, etc. 



It is changeable in coloration, its shade varying with that of the substratum on 

 which it occurs. It may appear in self-color in brownish olive, or in a striped 

 pattern in which a brown line on light background passes through eye to base 

 of caudal. 



It has been known a long time that in some of the species of Blennius and its 

 immediate allies there is a sexual difference in certain growths on the anal spines. 

 In B. marmoreus these organs are evident in males of 45 mm. and upward in 

 length. When they are fully developed they appear as 2 spherical or ellipsoidal 

 fleshy bulbs, borne on the anal spines, and roughened with longitudinal rugae or 

 lamellae. The female has no comparable structures. Her 1st anal spine is com- 

 pletely hidden by a flattened triangular fleshy shield of skin thickened at its 

 margin. 



