OCR Text |
Show 44 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, circular at the lower end than that of this species ; and the of it upward is irregular, there being a part of it which extends at an angle within the valve. These differences appear constant in the four specimens of M. fis-cherianus and the eleven of M. chorus which I have examined. The latter species is figured in Cunningham's ' Natural History of the Straits of Magellan,' on a plate opposite p. 155, under the name of Mytilus chilensis. This is not, however, the M. chilensis, Hupe. The largest specimen of M. fischerianus is 125 millims. long. MYTILUS, sp., jun. Hab. Station 7. There are two apparently young shells which I cannot identify with any described species. They are remarkable on account of the great breadth, which is about the same as the length. The sculpture too is very curious; it consists of 15 to 20 very thread-like lira? which radiate from the apex to the outer margin. The texture is thin, semitransparent, bluish white; and the surface is clothed with a thin pale-olive epidermis. MYTILUS MAGELLANICUS, Chemnitz. Hab. Station 3. PECTEN PATAGONICUS, King. Hab. Stations 1, 2, 3, 6, and Puerto Bueno, 2-7 fathoms, rocky bottom. BRACHIOPODA. WALDHEIMIA DILATATA, Lamarck. Hab. Stations 2, 3, 5, 7, and Cockle Cove, 2-32 fathoms, mud. One of the specimens from Portland Bay is very fine, having a diameter of 50 millims. WALDHEIMIA MAGELLANICA, Chemnitz. Hab. Stations 2, 5, and 7. V. POLYZOA. Bv STUART O. RIDLEY. (Plate VI.) For the systematic arrangement of the species here described, Mr. Hincks's most valuable recent work on the British Marine Polyzoa has been chiefly followed; the key to the generic relations of the species is therefore to be found there. I have hesitated to name many new species, preferring in some cases to designate as varieties forms which, were the known variability of recent forms and the number of readily identifiable and largely described fossil ones less than they are, would probably have been set down with little doubt as distinct species. |