612 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



and liigh, tlie posterior rays of both fins reaching at least to base of 

 caudal when depressed. Candal hmceolate, the middle rays produced, 

 2§ in body. Veutrals reaching vent, somewhat longer than pectorals, 

 wliich about equal length of head ; ventral sheath well developed, its 

 length two-sevenths that of fin. 



Body wholly covered with large, strongly ctenoid scales, which are 

 much reduced in size anteriorly ; head, ante-dorsal region, and breast 

 naked. 



In the female specimen, the mouth is evidently smaller, and the caudal 

 less elongate. 



99. Gobius thalassinus sp. nov. (29574.) 



Closely allied to G. emblematicus J. & G. 



Head and body translucent, overlaid by brilliant green luster, which 

 is formed by exceedingly minute close-set green points ; the luster is 

 intense towards the head, w^here it assumes a blue tint, and becomes 

 hardly noticeable on caudal i^eduncle; three conspicuous translucent 

 bars wider than the interspaces, crossing body immediately behind 

 head; head with tAVO brilliant narrow blue or green lines running 

 obliquely across cheeks below eye; opercle with greenish luster; 

 branchiostegal membrane white. Dorsals whitish, with two or three 

 lengthwise series of large reddish-brown spots ; spinous dorsal black- 

 ish at base. Upper caudal rays marked with red, the lower i^ortion of 

 caudal, and the most of the anal fin blackish, anal whitish at base, the 

 anterior rays tipped with brilliant white. Ventrals light buff. Pector- 

 als translucent. In spirits the body appears dusted with dark points ; 

 two light cross-bars towards head; lower part of caudal and anal 

 black. 



Head 3^ in length; depth 4^. D. VII-IO ; A. 15. 



Body elongate, mucli compressed, highest in front of ventrals, thence 

 tapering regularly to a very narrow, short, caudal peduncle; the body 

 with a peculiar, translucent, fragile ai)pearance, common also to G. 

 emblematicus. Head compressed, much higher than wide ; snout very 

 short, acute, the preorbital not as wide as pupil ; mouth terminal, very 

 wide and oblique, the jaws equal; maxillary reaching vertical from mid- 

 dle of orbit, one-half length of head; teeth in a narrow baud in each 

 jaw, the outer series enlarged, canine-like (under a microscope the band 

 of small teeth behind the outer series seems evident, but the size of our 

 specimens does not enable us to verify it with certainty) ; eyes placed 

 high, separated by a narrow ridge, the diameter about one-third length 

 of head. 



Dorsals very closely contiguous ; spines very slender, the fifth slightly 

 produced and filamentous, reaching (in our specimens) to base of third 

 soft ray when depressed ; caudal lanceolate, very long and pointed, the 

 middle rays produced, 2?- in body : pectorals as long as head; the upper 

 rays not silk-like ; ventrals with basal membrane well developed; the 



