232 REPORT ON ALBATROSS MOLLUSCA DALL. 



temperature at Stations 2772, 2775, 2777, 2778, 2779 arid at various 

 poiuts iu Magellan Straits. 



Bouchardia rosea Mawe. 

 Special search for this species was enjoined in the instructions to the 

 collectors of the expedition, as the soft parts are not yet known and 

 the shell is very peculiar. The only results were the dredging of a 

 number of valves and dead shells at Station 27G2, in south latitude 

 23° OS' and west longitude 41° 34', east of Rio Janeiro in 59 fathoms 

 mud and gravel; bottom temperature 57°. 1 F. 



Family TEREBRATULID.E. 



1*erebratulina cailleti Crosse. 

 This well known Antilleau species was obtained at Station 2750, off 

 St. Bartholomew, West Indies, in 496 fathoms sand, and at Stations 2752 

 and 2753 iu 2S1 fathoms sand off Santa Lucia, the bottom temperatures 

 ranging from 44°.4 to 48° F. 



Family LINGULIDJ3. 



Glottidia albida Hinds. 

 This species was dredged in 5 fathoms mud, off the coast of Lower 

 California, in north latitude 26° 42'. 



Family CRANIID.E. 



Crania pourtalesii Dall. 



Hab.— Station 2,781 in south latitude 51° 52' west, longitude 73° 

 41' on the west coast of Patagonia in 348 fathoms mud ; bottom tem- 

 perature 50° F. 



This species had previously been obtained only from the Florida 

 reefs and iu the Autiliean region in deep water. The discovery of it at 

 the present locality not only carries it southward to the Straits of Ma- 

 gellan but to the western coast of South America, where this genus has 

 not hitherto been known, either as recent or fossil. 



Class PELECYPODA. 



GENERAL CONSIDERATIONS. 

 •v » 



The attempt to divide the class Pelecypoda or Lamellibranchiata into 

 orders has so far been unsuccessful, or, at least, the subdivisions adopted 

 have from time to time been fouud unsatisfactory ou account of the 

 discovery of forms which combine in their organization characters 

 which had previously been regarded as diagnostic ot important subdi 

 visions, such as orders. 



This has resulted from the selection of characters as diagnostic which 

 are not really fundamental in the evolutionary history of the minor 



