430 
A. E. Yerrill — North American Cephalopods. 
The number of the foreign species, mostly nominal and imperfectly 
known, will undoubtedly be much reduced when they become 
better known. Probably A. dux and A. JBouyeri are identical, but 
there is as yet no proper zoological description of either. The 
former has been very briefly described by Gervais, and Harting has 
published an outline figure of one of the mandibles. 
Family M ASTIG-OTEUTHIDJE, nov. 
Body slender, pointed behind. Caudal fin large, rhombic. Mantle 
united to neck by three movable cartilages. Siphon with an inter- 
nal valve and one pair of dorsal bridles. Eyes large, not promi- 
nent ; lids free, simple. Buccal membrane 6-angled, without suckers. 
Arms free; suckers in two rows. Tentacular arms (in the typical 
species) not expanded into a club, the terminal portion round, taper- 
ing, covered with a multitude of minute suckers, in many rows. 
Neither auditory nor olfactory crests. Pen narrow, with a long, 
hollow posterior cone. 
This family differs from Ommastrephidce in lacking a distinct 
lachrymal sinus and olfactory frills, in the remarkable character of 
the tentacular arms, and in the simple connective cartilages. 
Mastigoteuthis Yerrill. (See p. 296). 
7. Mastigoteuthis Agassizii Yerrill. (p. 297). 
Family CHIROTEUTHID-iE Gray, (restricted). 
Loligopsidce (pars) D’Orb., Cephal. Acetab., p. 320. 1835—48. 
Chiroteuthidce (pars) Gray, Brit. Mus. Catal., Moll., voL i, p. 42, 1849. 
Body small; mantle with three movable connective cartilages. 
Eyes not prominent, with free, simple lids; no sinus. Siphon small, 
with an internal valve ; no dorsal bridle. Olfactory crests absent. 
Buccal membrane seven-angled, without suckers. Buccal aquiferous 
openings six. Sessile arms large; web rudimentary; suckers with 
toothed horny rings, encircled by a groove. Tentacular arms very 
long and slender, with a large club ; tip often with a spoon-shaped 
organ, opening backward ; peduncle with sessile connective suckers ; 
club with rows of singular small suckers, having a swollen bulb on 
the long pedicel. Pen with a long, narrow shaft, posterior portion 
involute, tubular. 
It is somewhat doubtful whether Calliteuthis belongs to this family, 
its tentacular arms being unknown. 
