1 84 Papers from the Marine Biological Laboratory at Tortugas. 



a number of years in a limited region about Woods Hole, Massachusetts, 

 and extending down to about 20 fathoms, yielded 83 species (see Osburn, 

 1912). Waters (1909-10) listed 73 species from the Red Sea. Norman 

 (1909) records 139 species from Madeira and neighboring islands. This 

 latter list is of special interest for comparison, since the Madeira bryozoa 

 have been collected with some care for about 50 years and it may be supposed 

 that it is fairly complete. In making comparison, however, it must be 

 noted that the dredging about Madeira extended down to 200 to 300 fathoms, 

 while those of the present list go only to 22 fathoms, so that to properly 

 compare the Florida with the Madeira fauna the present list of shallow- 

 water forms should be combined with that of Smitt. 



The Tortugas bryozoan fauna (shallow water) presents a very different 

 facies from that of Woods Hole at the same depth, since the two lists of 76 

 and 83 species, respectively, have only 13 species in common. The Woods 

 Hole fauna is distinctly northern, while that of the Tortugas, at least for 

 the shallow waters, is distinctly tropical. This is readily understood when 

 we recall that the Tortugas are within 0.5 degree of the tropics, and that 

 these islands receive, directly along their shores, the warm waters of the 

 Gulf Stream which sweep up from the Caribbean Sea. 



It is interesting to note in this connection that, of the 40 species here 

 added to Smitt's list, 33 are limited entirely or chiefly to a tropical distri- 

 bution. 



The arrangement of the bryozoan species, genera, and families has under- 

 gone so much alteration in recent years, as a result of the studies of Norman, 

 Waters, Calvet, and Levinsen, as to be wholly unintelligible to anyone except 

 the systematist familiar with the changes of the last ten years. It is im- 

 possible that this should be otherwise, since the older classification was 

 based almost entirely upon the structure of the skeleton of dead and dried 

 material, without reference to the general morphology. 



In the following list I have followed as far as possible the classification 

 adopted by Levinsen (1909). In the cases of a few imperfectly understood 

 species the older genera have been retained as "catch-alls." Thus the 

 genera (?) Lepralia and Phylactella have been used in the old Hincksian 

 sense for certain species which, with more complete knowledge, must un- 

 doubtedly go elsewhere. 



The figures were drawn by Mr. S. Shimitori, except figures 7, 11, 22, 

 and 23, which are the work of Mr. H. Murayama. 



ENTOPROCTA. 



Genus Pedicellina Sars, 1835. 



Pedicellina cernua (Pallas). 



Osburn, 1912, p. 213, Synonymy and previous records of the occurrence of this species 

 on the American coast. 



Apparently not common, but several small colonies were taken on the 

 piles of docks and dredged at 10 fathoms. 



