MUSEUM OF COMPARATIVE ZOOLOGY. 213 



Amusium (Propeamusimn) cancellatum Smith. 



Amussium cancellatum Smith, Challenger Rep. Lamellibranchs, p. 315, pi. xxiii. 



figs. 8 a- 8c. 1886. 

 ? Amussium fenestratum, var. cancellatum, Jeffreys, P. Z. S., 1879, p. 561. (Porcupine 



Exp. 1869, Station 37, 2435 fms.) 



Plate T. Figs. 1, 1 a, 2. 



Obtained by the Coast Survey steamer " Bache " in Charlotte Harbor, W. 

 Florida, in 13 fnis., 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 fms.; Stations 226 and 230, near St. 

 Vincent, in 424 and 464 fms. ; Station 236, off Beqnia, in 1591 fms., bottom 

 temperature 39°. 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 ; 

 tliere 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 lirse, and the remainder 

 ten to fourteen lirae internally. 



Amusium (Propeamusium) Hoskynsi Forbes. 



Pecten Hoskynsi Forbes, Rep. ^gean Sea, p. 192, 1843 ; Jeffreys (ex parte), Light- 

 ning and Porcupine Moll., P. Z. S., 1879, p. 502. 



Pecten concentricus Forbes, 1. c. (ex parte ; lower valve ?). 



Pecten Jimhriatus et antiquatus Philippi, Moll. Sic, II. p. 01, pi. xvi. figs. 5, 6 

 (upper and lower valves), 1844. 



Not P. Iloskynsi of G. 0. 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 belu-ig to A. cnncdlatuvi Smith (uou JefFreys). The ribs are 

 less clearly develope 1 than in most of the species, until the individual is fully 



