210 BULLETIN OF THE 



oflF St. Vincent, in 573 and 785 fms. ; Station 236, off Bequia, in 1591 fms., soft 

 mud; Stations 245 and 268, off Grenada, in 1058 and 955 fms.; Station 275, off 

 Barbados, in 218 fms. sand, bottom temperature 52°. 5 F. 



The bottom was, in all cases, sand, ooze, or mud, and the temperatures, except 

 those above cited, varied from 39° to 47°. 5 F., averaging about 41°.0 F. 



Amusium meridionale Smith would appear from the figures and description 

 closely to resemble the young of this species. Mr. Smith kindly informs me 

 that the form differs, and the sculpture of the deeper valve is not identical ; in 

 A. Dalli the valve is much more glossy and the radiating lirse are hardly ap- 

 parent. Mr. Smith thinks A. meridionale does not attain a large size. 



This elegant species was obtained by the "Challenger" as well as the 

 " Blake." It is evidently a true inhabitant of the deeps, although its range 

 is nearly 1400 fms. It is of extreme tenuity, and all the specimens obtained 

 were more or less broken about the margin. The adult valves are convex 

 nearly or quite to their edges, but the lower one while young has a concave 

 margination, as in the species of Propeamusium. Notes in regard to the 

 synonymy will be found under the head of Amusium Fourtalcsianum. 



The soft parts of this species present some features of interest. The ocular 

 papilla; or ocelli are present, but devoid of pigment. The mantle is slightly 

 tinged with purple. The gills are long, single on each side, and furnished 

 with long separate filaments much as in Dimya. There are no branchial 

 palpi, but the lips are produced to a very unusual length, forming an arch 

 over the space below the mouth, both upper and lower lips being equally pro- 

 longed and applied to each other in a sort of horseshoe-shaped manner. They 

 are internally concentrically rugose in the specimen, which may be due to 

 contraction caused by the alcohol. The ovary projects from tlie body between 

 the gills in the form of a legume ; from its anterior end spring'' the stalk of 

 the foot, which is slender, the groove being well marked; the distal end of the 

 foot is greatly enlarged, looking like the end of an Anatifa without a shell ; it 

 is dark purple, the only part of the animal so strongly pigmented ; the enlarge- 

 ment or "cornet" is hollow, the aperture, with a stout margin, looking for- 

 ward and downward; internally it is domed and radiately striate, being in fact 

 an exaggerated and efficient sucker, by means of which the animal should be 

 able to hold on to any flat surface, or (by expanding and contracting it like 

 the foot of Yoldia) to move about on the semifluid mud of the bottom. The 

 anua does not project from the surface to an appreciable extent. 



Section PROPEAMUSIUM De Gregorio (em.), 1883. 



Shell small, thin, vitreous, smooth or sculptured, the lower valve u-sually 

 concentrically waved and with a byssal notch, but no pectinium or byssal ser- 

 rations ; when adult internally lirate ; the upper valve smooth or sculptured, 

 but usually, if sculptured, with the radiating sculpture prominent; valves 

 closed, the lower one convex over the internal lirations, then angulated and 



