228 THE PLAGIOSTOMIA. 



Numerous lines of spine-like scales along the body and head, larger on the tail. 

 Dorsal spines prominent, hinder larger. Caudal short and rather deep. 



It is stated in the original description that the claspers are short and pro- 

 vided with four long sharp spines and that in order to accommodate these organs 

 the fins cross one another at right angles. The meaning of this is not at all 

 clear. The benefit reached by "crossing one another at right angles" is not 

 evident; besides, the figure published shows the ventral fins to be like those of 

 E. lucifer in which that position is hardly possible. 



Color: — above light brown, below darker; all fins pale yellowish brown. 

 Black areas and light stripes along the lower flank above the ventrals and forward, 

 like those on E. lucifer, are not indicated; if absent from E. brachyurus these 

 marks form additional means to distinguish the species. 



The type, an adult male of 8.5 inches, was taken near Jolo, at 263 fathoms. 



Etmopterus pusillus. 



Acanlhidium pusillum Lowe, 1839, Proc. Zool. soc. Lond., p. 91; 1849, Trans. Zool. soc. Lond., 3, p. 19. 

 Spinax pusillus Gunth., 1870, Cat. fishes Brit, mus., 8, p. 425; Vaillant, 1888, Travailleur et Talisman, 



Poissons, p. 72; Collett, 1890, Bull. Soc. zool. France, 15, p. 219; Regan, 1908, Ann. mag. nat. 



hist., scr. 8, 2, p. 44. 

 Etmopterus pusillus Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 55; Braganca, 1904, Res. 



inv. Amel., 2, p. 65, pi. 2, f. 2; Tanaka, 1912, Fishes of Japan, 6, p. 88, pi. 22. 

 Etmopterus frontimaculalus Pietschmann, 1907, Anz. Akad. vviss. Wien, 44, p. 395; 1908, Sitzb. Akad. 



wiss. Wien, 117, p. 654, pi. 1, f. 2, pi. 2, f. 2. 



Head little less than one fourth of the total length, depressed, crown slightly 

 convex transversely. Snout broad, length from the eye about equal the length 

 of the orbit, bluntly rounded at the end; nostrils midway from the end to the 

 eye. Eye large, orbit nearly half the preoral length, with a crescent-shaped 

 translucent area at the edge above the hinder half of the eye of possible utility 

 in connection with luminosity. Hind corner of the eye above the angle of the 

 mouth, near midway from the end of the snout to the pectoral. Mouth wide 

 with a deep groove and short labial folds on both jaws at the angles. Teeth 

 II; upper with a long straight median cusp and a short lateral one at each side 

 of its base, hindmost tooth like the lower; lower cutting edge obhque, the cusp 

 being obliquely turned toward the angle of the mouth. Pectorals not reaching 

 the origin of the first dorsal, subtruncate on hind margin, inner angle rounded. 

 First dorsal much narrower than the second; base without the spine little more 

 than half as long; spine midway from orbit to spine of second. Origin of second 

 dorsal above the axils of the ventrals; spine nearly twice the height of that of the 

 first, nearly as high as the fin; hind border of fin concave, hind angle much 



