MUSEUM OF COMPARATIVE ZOOLOGY. 213 
Amusium (Propeamusium) cancellatum Smirz. 
Amussium cancellatum Smith, Challenger Rep. Lamellibranchs, p. 315, pl. xxiii. 
figs. 8a-8c. 1886. 
% Amussium fenestratum, var. cancellatum, Jeffreys, P. Z. S., 1879, p. 561. (Porcupine 
Exp. 1869, Station 57, 2435 fms.) 
Plate V. Figs. 1, la, 2. 
Obtained by the Coast Survey steamer “ Bache” in Charlotte Harbor, W. 
Florida, in 13 fms., bottom temperature 82°.0 F.; by the “Blake,” off Cape San 
Antonio, in 424 fms.; in Yucatan Strait, in 640 fms.; at Station 19, in 310 fms.; 
Stations 51 and 61, near Havana, in 450 and 243 fms.; Station 128, in 180 fms.; 
Stations 130 and 136, in 451 and 508 fms., near Santa Cruz; Stations 150 and 
151, near Nevis, in 373 and 356 fms., bottom temperature 45°.0 ; Station 176, 
in 391 fms., and Station 188, in 372 fms., near Dominica; Stations 221 and 
222, near Santa Lucia, in 423 and 422 tms.; Stations 226 and 230, near St. 
Vincent, in 424 and 464 fms.; Station 236, off Bequia, in 1591 fms., bottom 
temperature 39°.0 F. With the exception of the first and last localities, the 
bottom temperature at the above stations ranged from 41°.5 to 60°.5 F. 
This fine species was found by the ‘‘ Challenger ” off Bermuda in 1075 fms., 
also off Culebra and St. Thomas. Many of the Blake specimens are more 
finely developed than those figured by Smith in the Challenger Report. It 
seems to have a wide geographical and bathymetrical range, and to be almost 
independent of temperature limits. The valves are tightly closed, the soft 
parts pale yellowish, with a narrow brown marginal line on the mantle edge ; 
there are no pigmented ocelli, the lips are wrinkled, the foot very short, deeply 
incised, without differentiated stem, and elongated instead of hood-shaped. 
The distal end of the intestine is free for a short distance. No byssus was 
observed. The young resemble the genuine fenestratum Fbs., but are more 
regular. Of those examined, 75 per cent had eleven lire, and the remainder 
ten to fourteen lire internally. 
Amusium (Propeamusium) Hoskynsi Forzes. 
Pecten Hoskynsi Forbes, Rep. AEgean Sea, p. 192, 1843; Jeffreys (ex parte), Light- 
ning and Porcupine Moll., P. Z. S., 1879, p. 562. 
Pecten concentricus Forbes, |. c. (ex parte ; lower valve 7). 
Pecten fimbriatus et antiquatus Philippi, Moll. Sic., II. p. 61, pl. xvi. figs. 5, 6 
(upper and lower valves), 1844. 
Not P. Hoskynsi of G. O. Sars, Leche, et al., of northern seas. 
This form has been obtained in the Mediterranean and the adjacent parts of 
the Atlantic. No authentic specimens are in the Jeffreys collection from the 
vicinity of America, the specimens so considered, mostly very young or imper- 
fect, appear to belong to A. cancellatum Smith (non Jeffreys). The ribs are 
less clearly developed than in most of the species, until the individual is fully 
