2268 Bulletin //, United States National Museum, 



value of its peculiarities, it is certain that it is not allied to Elacate any 

 more than to others of the hosts of Scombroid, Percoid, and kindred fishes, 

 and that it differs in toto from it, notwithstanding the claims that have 

 been made otherwise. It is true that there is a striking resemblance, 

 especially between the young almost as great, for example, as that 

 between the placeutal mouse and the marsupial Antechinomys but the 

 like is entirely superficial, and the scientific ichthyologist should be no 

 more misled in the case than would the scientific therologist by the 

 likeness of the marsupial and placental mammals." 



a. Body very slender, the vertebra? 14+16 = 30; ventrals narrowly aduate to abdomen; 



lower jaw produced in a flap; pectorals acute, with flexible rays. * 

 b. Lamina3 10 only. PHTHEIRICHTHYS, 833. 



bb. Lamina) 20 to 28. ECHENEIS, 834. 



aa. Body rather robust, the vertebra? 12+15=27; ventrals broadly adn ate to abdomen; 



lower jaw not produced; pectorals rounded. 



c. Laminae 24 to 27. REMILEGIA, 835. 



cc. Laminae 16 to 20. 



d. Pectoral rays soft and flexible. REMOEA, 836. 



dd. Pectoral rays stiff and ossified. RHOMBOCHIKUS, 837. 



833. PHTHEIRICHTHYS, Gill. 



Phtheirichthy i, GILL, Proc. Ac. Nat. Sci. Phila. 1862, 239 (lineata). 



Disk with 10 laminae ; palatines with sharp teeth ; teeth in pairs, uniform 

 in all ages; otherwise as in Echeneis. A single species, found attached to 

 spearfishes and Barracudas. (ifiQsip, a louse; i^v^ fish.) 



2602. PHTHEIRICHTHYS LINEATUS (Menzies). 



Head 5; disk twice as long as broad, its length 4.J in body. D. X-33; A. 

 33. Lower jaw very narrow, much projecting. Body blackish, with 2 

 whitish lateral bands; all the fins white-margined. Tropical seas, rang- 

 ing north to South Carolina and Pensacola ; rather rare, (lineatus, striped. ) 



Echeneis lineata, MENZIES, Trans. Linn. Soc. London, I, 1791, 187, pi. 17, fig. 1, Pacific Ocean 



between the tropics ; GtJNTHER, Cat., II, 382, 1860. . 



Echeneis tropica, EUPHRASEN, Nya Handl., xn, 317, 1791, Atlantic between the Tropics. 

 Echeneis apicalis, POEY, Memorias, n, 254, 1861, Cuba. (Coll. Poey.) 



Echeneis sphyrcenarum, POEY. Memorias, n, 255, 1861, Cuba, on Barracudas. (Coll. Poey.) 

 Phtheirichthy s lineatus, JORDAN & GILBERT, Synopsis, 969, 1883. 



834. ECHENEIS (Artedi) Linnaeus. 



Echeneis (ARTED:) LINN^OUS, Syst. Nat., Ed. x, 260, 1758 (naiicrates) . 



Leptecheneis, GlLL', Proc. Ac. Nat. Sci. Phila. 1864, 60 (naucrates) ; the name Echeneis being 

 transferred to E. remora, the only species known to Artedi. 



Body comparatively elongate, the vertebrae 14 + 16 = 30; disk long, of 

 20 to 28 laminae; pectoral pointed, its rays soft and flexible; soft dorsal 

 and anal long, of 30 to 41 rays each ; caudal lunate in the adult, convex in 

 the young. Species of wide distribution, attaching themselves mainly to 

 sea turtles and large fishes, (exwrfis, an ancient name, from s'xao, to 

 holdback; vav^ a ship.) 



