SERPULIDAE. 477 



table the general lines indicated by St. Joseph (Ann. sci. nat., 1894, 17, p. 259 ff.) 

 have been adopted where practicable as a basis. No effort at general revision 

 is made, the intent being to take up aU proposed genera so far as possible where 

 sufficiently tangible characters are available. 



Synonymy of Genera. 



The old genus Spirorbis Daudin has long presented difficulties, and its 

 study seems to have been avoided by most workers. The group, unquestionably 

 a natural one, is large, and probably only a small percentage of its forms have 

 been made known. St. Joseph's separation of the several genera into which he 

 divided it in such a way that other less closely related genera intervened, has met 

 with protest. Caullery and Mesnil (Buff, sci., 1897, 30, p. 183-233) in their 

 valuable study of the group recombine St. Joseph's genera in Spirorbis which 

 they then divide into subgenera to which they apply a whoUy new set of names 

 and for none of which they retain the name Spirorbis in a restricted sense. They 

 make the divisions primarily on the character of the coiling of the tube, whether 

 sinistral or dextral, making use then of the number of thoracic somites, place 

 of inculcation, character of the operculum and the setae. Miss Pixell in a more 

 recent study (Proc. Zool. soc. London, 1912, p. 792 et seq.) adopts these sub- 

 genera and adds another. But if these divisions are accepted they must in 

 part, under any conditions, bear names previously proposed. Thus Dexiospira 

 would have to be replaced by Circeis St. Joseph, the name being also preceded 

 by Janua and Mera of the same author, and Laeospira, containing the type of 

 Spirorbis, must give way to the latter, and includes besides the earlier Pileolaria 

 of Claparede. Miss Bush (Harriman Alaska Exped., 1910, 12, p. 256, etc.), 

 while in general protesting against the use of characters not detectable by the 

 naked eye or with a simple lens, for purposes of cataloging adopts groups 

 based on the character of the collar setae, essentially corresponding to St. Joseph's. 

 Whatever may be thought of the artificial character of the divisions proposed 

 by Caullery and Mesnil on the one hand, and those of St. Joseph on the other, 

 it seems that the more restricted groups arrived at by consideration of the 

 characters used in both cases are homogeneous and natural. Hence, since the 

 names are already available, I have restricted them as indicated in the key 

 under Spirorbinae, as it is proposed for convenience to designate the larger 

 group. I believe the characters of the setae primary to the others used, these 

 probably resulting from progressive adaptation to the tube as the latter acquired 



