FISHES OF THE PHOENIX AND SAMOAN ISLANDS 75 



116094, Tutuila Island, reef at Alofau, June 3, 1939, 2 specimens. 



116097, Canton Island, reef at ocean, April 25-28, 1939, 4 specimens. 



116098, Swains Island, reef, May 3-9, 1939, 3 specimens. 



Genus ICHTHYOCAMPUS Kaup 



Ichthiiocampus Kaup, Arcbiv Naturg., vol. 19, pt. 1, p. 231, 1853; Catalogue of the 

 lophobrancliiate fish in the collection of the British Museum, p. 29, 1856. 

 (Type, designated as /. 'belcheri Kaup by Jordan, Genera of lishes, pt. 2, 

 p. 253, 1919.) 



ICHTHYOCAMPUS DIACANTHUS, new species 

 PL \TE 8 



Holotype.—A specimen (probably female) (U. S. N. M. No. 116091), 

 without brood pouch, 67.7 mm. in standard length, taken by Leonard 

 P. Schultz on the reef of Tutuila Island at Alofau, June 3, 1939. 



Desciipfion. — (Based on the holotype, only known specimen.) The 

 following measurements of various characters have been converted into 

 hundredths of the standard length (67.7 mm.) : Tip of snout to front 

 of gill opening 12.6; tip of snout to rear of bony opercle 13.1; tip of 

 snout to front of orbit 5.9 ; diameter of eye 2.2 ; postorbital part of head 

 (front of gill opening) 4.6; rear of orbit to rear of bony opercle 5.1; 

 length of maxillaries 1.8; least width of bony interorbital space 1.3; 

 length of base of dorsal fin 10.2 ; length of longest dorsal fin ray 2.9 ; 

 length of longest caudal fin ray 1.8; length of longest pectoral fin ray 

 2,9 ; width of snout at one-half its length 1.8 ; greatest depth of body 

 5.9 ; depth of body at anus 5.2 ; width of body at anus 4.8 ; distance from 

 tip of snout to anus 46.3 ; anus to base of caudal fin 53.7 ; snout to origin 

 of dorsal fin 41.4. 



The following counts were made: Dorsal rays 21 + l^; anal 4; pec- 

 toral 14-14; rings 15 (trunk) +27 (caudal) ; dorsal fin on 2 trunk + 3 

 caudal rings ; 13 trunk rings before dorsal. 



The middorsal line of snout has a serrated keel ; at middle of upper 

 side of snout is a single small spiny projection; a strong supraorbital 

 ridge with a small spiny projection is prominent wdth a keel extend- 

 ing a sliort distance behind orbit; behind eyes and in front of the 

 nape occurs a middorsal keeled plate or spiny ridge, and behind this 

 is a less prominent keeled plate on nape ; a weak keel occurs on head 

 just above the opercle, on which is a small dermal flap; there are two 

 small keels just in front of base of pectoral fin; a small sharp keel 

 on base of opercle, with a dermal flap ; there is a series of tiny cirri 

 around the eye; other small cirri posteriorly near margin of opercle; 

 the interorbital space is deeply concave; each abdominal or trunk 

 ring has median cristae; the midventral line of the trunk rings are 

 weakly keeled, the surface is convex; the angles or cristae of each 

 ring are slightly rough, and become strong posteriorly and anteriorly, 



