452 ALBATROSS PTEROPODS AND HETEROPODS PECK. 



readied in her course 1 lie Galapagos Islands, lloiice it is that a com- 

 parison of the foregoing' tables of stations will show that the empty 

 shells, taken with the dredge, do not conform in locality to the exist- 

 ence of live animals at the surface taken by the two nets. This is partly 

 due to the fact that surface collecting was not always done at the same 

 time and i)lace as the bottom collecting, and even Avhen that was the 

 case the result was the same. In the deep-sea dredgings of the open 

 waters where the ])teropods are found, the surface and bottom collec- 

 tions for one station may not agree closely, whereas the averages of the 

 surface and bottom from a number of stations of the same region may 

 agree (|uite closely. Corresponding to dredging station 21~>(t, only 417 

 fathoms, the surface net took heteropods but no pteropods; while cor- 

 resi)onding: to a surface station 7, at which also heteropods only were 

 taken, was a dredging station 27r)."> in which shells (»f neither were taken 

 at 720 fathoms. tSo that from the individual position of the stations no 

 inferences can be drawn as to correlative existence between live pteropoda 

 at the surface and the ])resence of their dead shells at the bottom, over 

 the same area. Surface collections of pteropcxls may be i»resent with- 

 out the occurrence of like shells in collections of deposit at that point, 

 as shown at surface stat ion 2(>, as also de[)osit shells nuiy be taken with- 

 out the coi'resi>on(ling presence of live shells at surface, as at station 

 2750. But these dredgings would of themselves undoubtedly show that 

 at some seasons of the year and at some /onary depths, if not at the 

 surface, thes(^ molhisks exist in greater or less abundance throughout 

 the regions traxersed in the course of the Albatross 



()t the three families olTiiecosomatous Pteropoda, Limacinida^, Cav- 

 oliniida', and Cynd)uliida', the tirst is represented in these collections 

 only by two live specimens of Linuicina inflata, which were taken at 

 station 27")4, by the dredge, at a de])tli of 880 fathoms associated with 

 sixditferent sjiecies of Cavoliniida', all of which latter, however, were 

 represented only by empty shells. This would agree with llaeckel's 

 statement* that this jiarticular species is oiu' of those belonging to 

 zonary and bathybic faunte. The temperature at the bottom at this 

 point was 38° F., 46 degrees colder than that recorded for the surface 

 water, amounting almost to arctic temperature. 



The Cynd>uliida' are not represented in the collections in any way. 

 The Cavoliniida', on the other haiul, considering the fact that the col- 

 lecting: points at which they occur are so few, are (piite completely 

 represented both at surface and bottom At the dredging- stations all 

 the eight species of (V(ro////m, except o\w {t/lohidosa) ihc one species 

 of Cnvit'rina {columcUa) and six of the fourteen species of Clio, nearly 

 one-half are represented. Cavoliuiidje, in fact, were taken at eveiy- 

 one of the dredging stations as well as at each of the surface stations 

 where any pteropods were taken. Under this family of the eight spe- 



* Jenaische Zeitschrift fiir Naturwisseuscbiift, Fiinf und zwauzigste Bauds, p. 277 

 (Pteropodeu imd Heteropoden). 



