404 PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Soft parts in general as in tlie last species, except that the head and 

 mnzzle are much elongated, the sinns behind the head deep ; gill longer 

 and larger than in C. Rathlnmi, projecting out on the right side of the 

 head ; tentacles longer and foot shorter proportionally than in C. Ratli- 

 huni; the mantle margin is much puckered, but this is i)robably due to 

 the alcohol ; the margination, which forms a semilunar area at the end 

 of the mnzzle in the preceding species, in G. Beanii is interrupted be- 

 fore the papillose area which here distinctly forms the end of the muz- 

 zle, the effect of which is to produce two lappets, one on each side, 

 extending from the end of the muzzle to the anterior edge of the foot. 

 There appears to be no jaw. 



Dentiticn. — In this species the bands of iincini are proportionally 

 longer and wider and the rhachidian tooth smaller than in the preceding. 

 The rhachidian tooth is small, with a tridentate cusp and bifurcate base; 

 it is about half as long as and hardlj' wider than the first three laterals; 

 the latter are elongate, slender, with denticulate cusps, the outer is 

 rather the shorter in the mature part of the radula ; the major lateral 

 is longer, with a more slender shaft than in C. Rathhuni, and a projjor- 

 tionally larger, very concave cusp with seven or eight denticulations; 

 the banded uncini nre singly broader than in C. Rathhtmi, and collect- 

 ively about one-half longer. 



Eahitai.— Station 871, U. S. Fish Commission, lat. 40° 02' 54" K, 

 Ion. 70° 23' 40" W., in 115 fathoms muddy sand ; station 894, U. S. Fish 

 Commission, lat. 39o 53' N., Ion. 70° 58' 30" W., 3G5 fathoms mud and 

 gravel, both in 1880; station 947, 312 fathoms sandy mud, bottom tem- 

 perature 44° F. ; station 949, 79J miles south of Martha's Vineyard, in 

 100 fathoms yellow mud, bottom temperature 52o.O, surface 6G°.0 F. ; 

 station 997, 335 fathoms, yellow mud, bottom temperature 40° F. ; these 

 last in 1881 (Verrill); and from the same localities as C. Rathbiini in the 

 West Indies (Agassiz), with the additional locality of station 264, 416 

 fathoms gray ooze, off Grenada, bottom temperature 42°.5 F.* It is 

 named in honor of Dr. T. H. Beau, of the United States Fish Com- 

 mission. 



Family ADDISONIID^ Dall. 



Shell asymmetrical, porcellanous, somewhat like Capidacmcea Sars. 



Soft parts much as in the last family, but strongly asymmetrical, 

 with an enormously developed lateral series of separately inserted gill- 

 laminte, like those of Patellidcv, and without filamentary appendages of 

 any kind. Radula with a large simple rhachidian tooth with, on each 

 side, two large simple transverse laterals, followed by two minute ones, 

 and a large outer lateral with a strong tridentate cusp, outside of which 



*This is, perhaps, the shell referred to under the name of "Acmwa ruhella'^ Fabr." 

 Verrill, Proc. U. S. Nat. Mus., Ill, p. 391, dredged (dead) at station 894, United States 

 Fish Commission, 1880, off the S. E. coast of New England, in 39° 53' N., 70° 58' 30" 

 W. , in 365 fathoms. 



