DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 283 



Tliis form, originally described from Greenland, has since been found also on the coast 

 of I^orway and about Iceland and Spitzbergeu. Giinther states, on what aixthority we are 

 not aware, that it also occurs about Newfoundland. Although characteristically littoral, it 

 has been found at a depth of 250 fathoms. 



BATHYAGONUS, Gilbert. 

 Bathyagomis, Gilbert, Proc. U. S. Nat. Mus., xii, 1890, 89. 



Spinous dorsal developed. Lower jaw the l<mgcr. Plates of body spinous. Gill mem- 

 branes united to the isthmus, not forming a fold across it. Teeth well developed on jaws, 

 vomer, and palatines. Pectorals not notched, the npper rays the longest, the lower becom- 

 ing regularly shortened. Bones of head thin and yielding, the system of mucous canals 

 very strongly developed. (Cfilbvrt.) 



This genus is represented by one species, Bathyagomis nigripinnis, Gilbert, obtained by 

 the U. S. Fish Commission steamer Albatross off the coast of California in 477 fathoms. 



XENOCHIRUS, Gilbert. 

 XenocMrus, Gilbert, Proc. U. S. Nat. Mus., xiii, 1890, 91. 



Spinous dorsal present. Jaws equal, or the upper the longest. Plates of body spinous. 

 Gill membranes united to the isthmus, the posterior edge sometimes forming a very narrow 

 free fold across the throat. Teeth well developed on jaws, vomer, and palatines. Pectorals 

 divided by a ueep notch into two portions, the lower composed of greatly thickened rays, 

 which are simple and frecjuently longer than those of the upper lobe. A series of small 

 spines on eyeball above pupil. {Gilbert.) 



This genus, allied to I'odothccus, is represented by two species recently taken by the 

 U. S. Fish Commission steamerAi&((iros«off the coast of California — X. triacanthus, Gilbert, 

 from 77 to 145 fathoms, and A', pentacanthus, Gilbert, in 178 fathoms. 



ASPIDOPHOROIDES, Lacepede. 



Aspidojylioroides, LAClsipfeDE, Hist. Nat. Poiss., in, 1802, 228,: (type, Aspidophoroidestranquehar, 'La.c.^Coittis 



moiioptei'jigius, Blocli). 

 Anoplagonus, Gill, Proc. Acad. Nat. Sc. Phila., 1861,167, 259. 



Body very long and slender, subterete, octangular, tapering into a very long six-sided 

 tail. Head slender, short, with large eye; mouth small, terminal; jaws and vomer with 

 villiform teeth. Dorsal fin single, without spines, very small, inserted nearly opposite the 

 still smaller anal; other fins smaU; bony plates of body keeled, without spines; gill-mem- 

 branes broadly united, free from the isthmus. {Jordan and Gilbert.) 



ASPIDOPHOROIDES MONOPTERYGIUS, (Block). (Figure 260.) 



Coitus monopterijfiiiis, Bloch, Ausliiud. Fisclio, ii, 156, taf. 178. — Richardson, Fauna Bor.-Amer., Fishes, 50. 



AgonuH monopiei-ygius, Schneider, Bloch's S^st. Ichth., 1801, 101. 



Aapidophorim monopterijgim, CuviER and Valenciexnes, Hist. Nat. Poiss., iv, 224; vi, 55-t, pi. CLXix. — 



GiJNTHER, Cat. Fish. Brit. Mus., ii, 216. 

 Aspidophoroides momptcnjgiiis, Goode and Bean, Amer. Jour. Sci. and Arts, 1877, 477.— Goode, Proc. 



U. S. Nat. Mus., 1880, 480.— Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., 725. 



Body slender, elongate, its height 9 in its length. Head triangular, nmch narrowed 

 anteriorly, its length 5§ in that of body; nasal spines very large, diverging, inserted near 

 tip of snout; no other spines anywhere; eyes very large, longer than snout; supraocular 

 ridges very high; a ridge extending backward from eye along temporal region ; lower jaw 

 slightly included; caudal peduncle very long and slender, forming about two-fifths tbe 

 length; breast with flat plates; dorsal ridges high anteriorly, the median line of back from 

 snout to dorsal flu concave. Head 5§; depth 9. 



Radial formula: I). 5; A. G; L. lat. ca. 50. 



Color brownish, obscurely banded with darker; pectorals, dorsal, and caudal mottled or 

 barred. 



