[115] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 325 



Mastigotettthis Verrill. 



Trans. Conn. Acad., vol. v, p. 296, Jan., 1881 ; Bulletin Mus. Comp. Zool., vol. viii, p. 

 100, March, 1881. 



Body elongated, tapering to a point, eonfluent with the caudal fin 

 posteriorly. Caudal fin very large and broad, rhomboidal, occupying 

 about half the length of the body. Mantle fastened to the base of the 

 siphon by an ovate, ear-shaped, elevated cartilage, on each side, fitting 

 into corresponding deep, circumscribed pits on the base of the siphon. 

 Siphon with a bilabiate aperture, an internal valve, and a pair of dorsal 

 bridles. Eyes large, with round pupils ; lids free, thin, apparently with 

 a very small anterior sinus. Arms very unequal, the ventral ones much 

 the longest. Suckers small, in two regular rows. Tentacular arms long 

 and round, tapering to the tips, shaped like a whip-lash, without any 

 distinct club ; the distal portion is covered nearly all around with ex- 

 ceedingly numerous and minute suckers, which leave only a very narrow 

 naked line along the outside. Pen narrow and bicostate anteriorly, very 

 slender in the middle ; posteriorly much larger, with a long tubular 

 cone (figs. 1 b, 1 c). This remarkable genus differs widely from all others 

 hitherto described in the character of the tentacular arms and suckers. 

 This, with the great size of the caudal fin, gives a very peculiar aspect to 

 the species. 



Mastigoteuthis Agassizii Verrill. 



Bulletin Mus. Comp. Zool., vol. viii, p. 100, pi. 1, fig. 1, pi. 2, figs. 2, 3-3 e, 1881 ; 

 Trans. Conn. Acad., vol. v, p. 297, pi. 47, pi. 49, figs. 2, 3-3 e, Jau., 1881. 



Plate XXI. Plate XXII, figures 2-2 d. 



Body elongated, round anteriorly; posteriorly tapering rapidly to the 

 slender, acute, terminal portion, which is confluent with the caudal fin 

 to the tip. Front dorsal edge of mantle emarginate in the middle. 

 Caudal fin very large and broad, transversely rhomboidal, obtuse pos- 

 teriorly, its length, from origin to tip, about equal to half the combined 

 length of the head and body. Eyes large, with thin lids, which appear 

 to have had a distinct but very small sinus in front ; pupils circular ; 

 iris brown, in alcohol. Sessile arms very unequal ; ventral arms much 

 larger and longer than the others, about equal to length of head and 

 body; dorsal arms very small, scarcely one-third the length of the ventral 

 pair ; two lateral pairs nearly equal, decidedly longer and stouter than 

 the dorsal pair. A delicate, thin, marginal membrane extends along the 

 arms, outside the rows of suckers, to the slender tips. Suckers small, 

 in two regular rows on all the arms, subglobular, with small oblique 

 apertures, surrounded by small horny rings, which have a nearly entire 

 margin, and by several series of minute plates (Plate XXII, fig. 2 d). 



Basal web, between the arms, very small. In the smaller specimen, 

 which is a male, the right ventral arm is longer than the left, and the 

 tip appears to have been flattened, and the marginal membranes seem 



