DISCUSSION OF SPECIES AJsD THEIR DISTRIBUTION. 53 



Family MICROSTOMIDvE. 



Microslomaloida;, Gill, Cat. Fish. E. Coast, N. A., 18G1, 54. 

 Microtituiiihlii, Gill, Arr. Fain. Fi.'fhes, 1872, IG. 



The fiiinily Microstomlda', although ucver fornially dcfiucHl by Dr. Gill, is evidently a 

 valid one, separated from Arcjnitinidw by the much .siualler nund)er of branch iost(!<;al 

 rays, only three or four, iu.stea(l of .six to eight, a.s in Argent in idw. Tlie advanced position 

 of the ventrals is a collateral character. 



MICROSTOMA, Cuvier. 



Microstoma, CuviER, Ri-ijue Animal, Lst eil., 1817, ii, 181; 18i;9, ii, 285.— Gi-NTHER, Cat. Fish. Brit. Mus., 

 VI, 201; Challfuger Report, xxii, 218. 



Microstomids, with small mouth, small int(>rinaxillarie.s., short and broad maxillaries. 

 Small teeth, in narrow .series iu lower Jaw, and on head of vomer. Ventrals in front of dor- 

 sal. Caudal fin furcate, its base squamose. Braiichiostegals, 3-4. Pyloric caica ab.seut. 

 Air bladder large. Scales large, thin, silvery. Adipo.se fin absent in adults. 



"The evidence as to the bathybial habits of these small Hshes,'' writes Giintlier, "is 

 merely circumstantial. They seem to have the same vertical range as Argentinn, but are 

 more rarely seen in collections, as the small size of their slender cylindrical body renders 

 their capture very difticult." 



MICROSTOMA ROTUNDATUM, (Risso), Guntuer. (Figiiio 59.) 



Gastero2>elccus microstoma, Ris.su, Ichth. Nice, 1810, .S56. 



Mieroitoma microstoma, Cuvier, Regne Animal, eil. 1, 1817, ii, 184; eil. 2, 182i), 285. 



Microstoma rotundata, Risso, Eur. Merid., 1827, iii, 475, fiij. xxxvi. 



Microstoma rotundatum, Gt'rxTHER, Cat. Fish. Brit. Mus., vi, 201. — Canestrini, op. cit., 130. 



Microstoma argentcum, Cltvier and Valenciexxes, Hist. Nat. Poiss., xviu, 358, pi. 544. 



Body cylindrical, mouth small. Height of body 10 to 11 in length. Diameter of eye 2i in 

 length of head, the latter 5h in total length. Ventrals midway from base of caudal and base 

 of pectoral. Adipose fin usually wanting. Sihery. 



Radial formula: 1). !»-ll; A. 8; P. 8; V. 10; L. lat. 52. 



Known only from Nice and Sicily. It is placed among bathybial forms in deference to 

 the opinion of Dr. (xiinther already quoted. The National Museum has a sjiecimen (No. 

 40072) from ilessina, sent by the Florence Museum, one of tiftceu examples of this very 

 rare form, taken by Giglioli, September 2.')-28, 187r>. 



We have had no opportunity of examining another Mediterranean form recently described 

 by Facciola (Microstuma iMitHm, Facciohi, Natnralista Siciliana VI, I'Jo.) 



MICROSrOM.V <iR(T:NLANDICUM, Reiniiai'.dt. 



Microstomiix (ira-iitaiidiciis, Reixiiaudt, Vid. Selsk. Naturvid. og Math. Afliaudl., \lir, ISll, lxxi%-. 

 Microstoma ijrwnlamlicKm, GOnther, Cat. Fish. Brit. Mus., VI, 205.— Gill, Cat. Fish. E. C. N. .-Vmer. 



"Height of body 10 in length. Length of head 5 in same. Ventrals under posterior 

 part of ventrals. Adipose fin conspicuous." 



Radial formula: D. 11 ; A. 10; V. 10. 



This form was found at an early day in the waters of Greenland, but has not since been 

 observed. 



Family BATH YLAGID^^. 



BattujJagidw, Gill, Science, iii, (i20. issi. (Name ouly.) 



The family BalhyUgidcv of Gill was formed for the genus Bnfhyhifius of Giinther. This 

 genus includes five species of small fishes, one of them (Z>. athtiitirns) occurring in the 

 Atlantic in de])ths as great as 2,040 fathoms, another {B. antarctici(n) inhabiting the Ant- 

 axctic Ocean at a depth of 1,950 fathoms, and a third {B. pacijicus) occurring ofl' the coast 



