76 BULLETIN 180, UNITED STATES NATIONAL MUSEUM 



there are no spiny projections but the posterior end of each cristae on 

 the tail becomes increasingly sharp pointed posteriorly. 



Color brown, darker behind dorsal fin and pale dorsally in front 

 of dorsal fin ; a black spot around base of first dorsal ray and another 

 at base of last dorsal ray ; in front of base of caudal fin the last three 

 tail rings are white, the basal two-thirds of the caudal fin blackish 

 but the margin white; in front of the dorsal there are two narrow 

 pale bars, another at middle of dorsal fin, and four behind it ; there 

 is a series of dark dots along the upper edges of the inferior trunk 

 cristae ; a few irregularly placed dark spots between the median and 

 dorsal cristae on the trunk; a black spot at upper edge of pectoral 

 fin base. 



Remarks. — This new species of Ichthyocampus differs from all 

 other species in the genus with the superior and inferior cristae of 

 trunk continuous with tlie same cristae on the tail in having but 21 

 dorsal rays and only 15 + 27 rings except /. Tcampeni Weber and 

 /. helcheri Kaup; all the other species reported have more than 22 

 dorsal rays and more than 16 + 30 rings. From /. kampeni Weber 

 the new species differs in coloration; there are but four pale bars 

 behind the dorsal in diacanthus instead of seven, and the last three 

 tail rings are white instead of blackish as in kampeni; diacanthus has 

 cutaneous appendages on the head and kampeni none; supraorbital 

 ridges of diacanthus strong and spinelike, almost absent on kampeni. 



I. diacanthus differs from /. heJcheH Kaup in having the dorsal 

 origin on the fourteenth trunk ring instead of on the "second caudal 

 ring,"^ and Kaup' says that the "dorsal fin stands on 5 rings, the 

 anal ring being the first of them" ; the operculum of helcheH is with- 

 out a keel, while diacanthus has a strong keel basally ; no dermal cirri 

 or cutaneous flaps are mentioned as occurring on 'belcheH^ while sev- 

 eral occur on the new species. 



Named diacanthus in reference to the two spiny projections, one 

 over each orbit, bearing a short dermal flap. 



Order AULOSTOMI 



Family AULOSTOMIDAE 



Genus AULOSTOMUS Lacepede 



Aulostomus Lacep£de, Histoire naturelle des poissons, vol. 3, p. 3;")6, 1803 

 [Type, Aulostomus chinensis Lacepede {=Fistularia chinensis Linnaeus).] 



AULOSTOMUS CHINENSIS (Linnaena) 



Fistularia chinensis Linnaeus, Systems naturae, od. 12, p. 515, 1766. 



115196, Canton Island, lagoon, May 23-25, 1939, 1 specimen. 

 52525, Apia, Samoa, Jordan and Kellogg, 1 specimen. 



• GQnther, Catalogue of the fishes of the British Museum, vol. 8, p. 177, 1870. 

 ' Catalogue of the lophobranchiate fish in the collection of the British Museum, p. 30, 

 1856. 



