DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 51 



PTEROTHRISSUS, Hilgendorf. 



Pterotkrbaus, Bilgehdorf, A.ct. Soc. I poldina Carol., xm, Nos. 1"', 16, September 3, 1877, 127. — Sitz- 



ongsber. Naturf. Frennde, 1878, L56; L887, L87. 

 Bathythrissa, GCnther, Aim. and Mag. Nat. llist..x\, 1877 (November 1), 433.— Challenger Report, xxn, 220. 



•■ Body covered with scales of moderate size; head narrow, oblong, with mucilerous chan 

 nels much developed. Eye Large. Mouth narrow, coregonoid, with bands of minute teeth 

 embedded in the thick lips: maxillary with a marginal row of very small teeth. Caudal fin 

 forked, with a dense layer of small scales. Air bladder with very thick walls, terminating 

 in two short horns in front, pointed behind." (GHinther.) 



Pterothrissus was published September •">, 1877, and Bathythrissa, November 1, 1877. 

 (See Sitzungsberichte, UTaturforschende Frewide, L887, No. 9, 187, 188. 



The genus and family are known only from a single species, P. gissu, Hilgendorf 

 (Figure 52) [= Bathythrissa dorsalis, (murker. Challenger Report, xxn, 222, pi. lvi, fig. A], 

 from Japan taken in 345 ( .') fathoms. 



Family ARGENTINID^. 



Argentinina; Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., 1883, 288. 

 Argentinidw, Gill. Smithsonian Report, 1884, 619. Jordan. Cat. Fish. N. A., 1885, 42. 



Body elongate; scales cycloid. Head naked. Month terminal, small or moderate; the 

 maxillary forming the lateral margin of the upper jaw: a supplemental maxillary bone; pre- 

 inaxillaries not protractile. Teeth in jaws absent. Four gills, a slit behind the last. Pseu 

 dobranchiae present, Gill membranes separate, free from the isthmus. Branchiostegals 

 six or mure. Dorsal short, nearly median ; adipose fin present. Caudal tin forked. Anal 

 fin moderate. Ventrals under the dorsal, nearly median, of moderate length, rays 9 to 1 1. 

 Pectorals placed low. A lateral line. Air bladder large. Stomach caeeal. Pyloric caeca 

 lew or none. 



ARGENTINA, Artedi. 



Argentina, Artedi, Genera Pisciutn, 8.— C'rviEii. Regne Animal, 2d ed., 1829, n, 308. — Gill, Proc. Aead. 

 Nat. Sci. Phila., 1862, 15.— GCnther, Cat. Fish. Brit. Mus., VI, 202. 



Body fusiform, with mouth small; mamillaries and intermaxillaries short, the upper 

 jaw not reaching to vertical from anterior margin of orbit. Jaws toothless. Minute 

 teeth on head of vomer and on palatines in front. Tongue toothed. Ventrals behind dor- 

 sal. Caudal furcate. Branchiostegals well developed, 6-8. Pyloric cceca present in mod- 

 erate numbers. Scales rather large. 



KEV TO THE SPECIES OF ARGENTINA. 



A. Scales spinigerous. 



1. Body low (height 8 in total). Diameter of eye less than or equal to snout A. sphyr.ena 



2. Body high (5 to 5 k in height). Diameter of eye greater than length of snout .A. silus 



B. Scales smooth. 



1. Body low. 



A. Diameter of eye greater than length of snout; height of body 7 in total A. striata 



B. Diameter of eye less than length of snout; height of body 8 in total A. elongata 



ARGENTINA Sl'H YK.ENA, Linn.eis. 



Sphyrana parva, Rondeletius, Libri de Piscibus Marinis, 1551. r. 227.— Gesxer, Fischbnch, 1558, 883, 1061. 



Argentina, \Vii,i.i-<;hhy, 1686.— Eat, 1713.— Artedi, 1738. 



Argentina sphyrcena, I.ixx.Krs, Syst. Nat., ed., xn, 1766, i. 513. — Ri-.so. [chth. Nice, 336.— Nilsson, Skand 



Faun., Fisk., 476. — GCnther, Cat. Fish. Brit. Mus.. vi. 203; Challenger Report, XXII, 218.— Canestrini,. 



Fauna d'ltalia, Pesci, 12ii.— Collett, Norges Fi>kc 171; Forhandl, Vid. Sclsk. Christ., 1880, 92.— 

 Giglioli, Elenco, 102. 

 GonioHoma argent in urn. COSTA, Fauna Napolitana, pi. xxxvi. 

 Osmcru* hebridicas, Vauri'.i.l, Brit. Fish., 2d ed., n. 133. 



