THE NAUTILUS. 19 



MOLLUSCA. 



Nucula belloti A. Adams. One live specimen from about 40 

 fathoms. 



Leda tapkria Dall. Many empty valves and a few small live spe- 

 cimens were obtained almost everywhere that we dredged in the bay. 

 12 to 40 fathoms. 



Leda hamata Carpenter. Occasionally found with. the preceding. 



Barbatia gradata Sowerby. Living; 12 fathoms. 



Glycimeris intermedia Broderip. No living specimens were ob- 

 tained, but fresh valves were dredged in twelve fathoms of water. 



Philobrya setosa Carpenter. 12 fathoms. Found attached by its 

 byssus to bunches of coralline, which it closely resembles in color 

 and is exceedingly difficult to distinguish. Not rare, and many were 

 doubtless thrown away before we discovered the habitat of this tiny 

 but none the less interesting mollusk. 



Mytilus californianus Conrad. This animal covers the rocks just 

 above the low-water mark and may be gathered by the tubful, if one 

 is willing to risk the almost certain wetting he will get, if he clam- 

 bers too far out on the exposed headlands, which are the mussel's 

 favorite haunts. 



Septifer bifurcatus Reeve. Not rare between tides. 



Modiolus fornicatus Carpenter. 12 to 40 fathoms. 



Modiolus rectus Conr. 20 fathoms. 



Modiolus rectus var. flabellatus Gould. One enormous specimen of 

 this variety was obtained which had been brought in by the fisher- 

 men. It far exceeds in size any other Mytilid in my cabinet. 



Adula falcata Gould. Living in the hard blue clay with other 

 borers. 12 fathoms. 



Lithophagus plumula Hanley. With the above ; not uncommon. 



Crenella divaricata Orbigny. 25 fathoms. 



Pecten hastatus Sowerby. 12-40 fathoms. No very large or 

 brightly-colored specimens were obtained. 



Pecten hericeus Gould. One fine valve came up in the dredge 

 from the blue clay region off Del Monte. 12 fathoms. 



Pecten diegensis Dall. Young specimens were dredged with P, 

 hericeus and P. hastatus. The fishermen sometimes bring in beau- 

 tiful adult specimens from the coral banks. 



Pecten (Hinnites) giganteus Gray. A few were found at low-tide 

 attached to the under surfaces of rocks. At the great Tide Pool, 



