ICHTHYOLOGICAL COLLECTIONS OF THE ALBATEOSS. 



425 



immediately behind the eye, the second and third approximated at posterior end of 

 ridge. These bear no cirri. G. tricHspis has no tubercles on occiput. 



In males of G. pistUUger the postaxial region is furuished with a number of very 

 slender filaments, each of which is expanded at tip into a compressed frond-like 

 lamina, having the free edge more or less laciniate or fringed. These expanded tips 

 are bright white and very conspicuous. No trace of them is present in females, but 

 they develop in males at a very early age. These agree with the structures described 

 by Pallas, on which he based the name pistilliger. They seem to be absent in G. 

 tricuspis. 



The upper preopercular spine is sharply bifurcate in even our smallest specimens 

 (50 mm.), but in these no trace of a second medial upwardly directed spine is 

 present. The latter is evident in specimens 70 mm. and more in length, and a small 

 concealed prominence representing a third spine is exceptionally present. 



The following table gives in millimeters the total length, the depth of body, and 

 length of head in eight specimens : 



Very young specimens show no groups of granulations on head or nape, these being 

 usually wanting in specimens less than 100 mm. long. In older specimens they are 

 variously developed, the degree of armature dependent neither on age nor sex. They 

 are never armed on interorbital space, being unlike G. galeatus in this respect, the 

 granulations being confined to the occipital and nuchal regions, with an additional 

 elongate patch on the upper part of the opercle. In highly developed males the 

 dorsal and ventral rays are accompanied with series of tubercles. 



The color is brown above, with very narrow vermiculating lines of lighter; a 

 black blotch on cheeks, more conspicuous in males, and four inconspicuous crossbars 

 on back. The darker dorsal area is bounded below lateral line by an irregular 

 series of dark streaks or blotches. In males the lower jaw and preopercle are 

 cross-banded with black and light yellow ; the abdomen, the lower half of sides in 

 front of anus, and the prepectoral region, have large roundish white spots, separated 

 by vermiculating areas rendered dusky by aggregations of coarse black dots. 

 Ventrals dusky and silvery, the latter frequently forming crossbands. Spinous 

 dorsal dusky or black, with irregular series of whit^ spots not confined to basal 

 parts of fin. In both sexes the pectorals, second dorsal, and caudal are translucent 

 or yellowish, crossed by narrow black bars. 



The females are more numerous than the males in our collection, but the disparity 

 in numbers is not so great as has been found by other writers. In 45 specimens 

 examined as to this, 17 are males, 28 females. Taken abundantly in Bristol Bay at 

 stations 3230, 3231, 3232, 3233, 3237, 3238, 3239, 3240, 3241, 3242, 3243, 3244, 3245, 3246, 

 3289, 3291, 3296, 3300; depths, 3i to 26 fathoms. 



67. Gymnacanthus galeatus Bean. 



A single male specimen, 210 mm. long, from Chernoffski Harbor, Unalaska Island. 

 The sexual peculiarities are less strongly marked than in much smaller males of 

 G. pistiUiger. 



The ventrals extend but little beyond the front of the anal fin, and are unmarked. 

 The abdomen is also plain, without the round white spots characteristic of male 



