654 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



as from all other species of Chactodon the present species differs 

 generically in the extraordinary development of the spinous dorsal, 

 which characterizes the genus Loa, named for the great volcano, the 

 eruption of which brought this strange fish to light. 



Family PERISTEDIIDAE. 



PERISTEDION ENGYCEROS Gunther. 



Peristethus engycerqg Gunther, Proc. Zool. Soc. London, 1871, p. 663; "Sandwich 

 Islands"; Fische der Siidsee, p. 168. 



A large example, 13£ inches long, in good condition, except being 

 dried in the sun. It is apparently identical with Peristethus engy- 

 ceros, described by Gunther, from "dried fragments from the Sand- 

 wich Islands." 



A second specimen of the same species, 6 inches long, identical 

 with this in color and details, I find among the duplicates from the 

 Albatross collection of 1902, described by Dr. C. H. Gilbert. 1 



v --_ 



FlG. 7.— PERISTEDION ENGYCEROS Gt)NTHER. 



In most respects these two specimens agree with Doctor Gilbert's 

 description and with such of the duplicates on which it is based, as 

 have become part of the Stanford University collections. The differ- 

 ences, however, indicate two distinct species, the second of which I 

 propose to call Peristedion gilberti, taking as a type, Cat. No. 84102, 

 U.S.N.M., obtained by the Albatross off Oahu or Maui. 



In Peristedion engyceros the prolongations of the snout are not 

 quite parallel, but diverge visibly, being nearly half farther apart at 

 tip than at base; the interorbital space is broader than the vertical 

 diameter of the eye; the preopercular spine is 1\ in the length of the 

 prolonged spines: The dorsal rays are VII-22: anal, 22: pectoral, 

 13 + 2, reaching to the seventh lateral scute, If in head with the 

 spines. Ventrals nearly reaching front of anal; pectoral considerably 

 beyond. 



Body with four broad blackish cross bars, one under spinous dorsal ; 

 two under soft dorsal and one near base of caudal, the first broadest; 



» Deep Sea Fishes of the Hawaiian Islands, 1905, p. 639. 



