SABELLIDES AND SERPULIDES 255 



setigerous segments, some maintain that the ova are found only in the 

 first two or three of these segments, others that they occur only in 

 the middle or body-cavity, which ruptures along its convex side, per- 

 mitting the eggs to escape into the tube, where they are developed. In 

 preserved specimens of S. spirorbis strings or chains of embryos show- 

 ing well-formed setae have been found lying along the back, apparently 

 coming from an opening in the body-cavity just back of the thorax. 

 In several specimens, when stained and mounted, eggs showing nucleus 

 and nucleolus have been seen in both the body-cavity and (smaller 

 ones) in the first few posterior segments, but no spermatozoa were 

 noticed, the posterior segments being usually filled with minute gran- 

 ules (oil drops?), with the mucous glands on their dorsal surface 

 very conspicuous, especially when eggs were found in the tube. Miss 

 Schively, however, who carried on her investigations during two sea- 

 sons, examining specimens from eight different localities in Vineyard 

 Sound and Buzzard's Bay, states "that S. borealis has two breeding 

 seasons. One of these extends from the middle of June to the middle 

 of July ; the other extends through the month of August. During the 

 last two weeks of July no eggs were found either in the body-cavity or 

 in the shell." "The eggs pass out through the operculum ; its end 

 bears a movable translucent plate of lime, etc." " The reproductive 

 glands are arranged on either side of the intestinal canal near the 

 stomach. Where the ova and sperm is developed is distinguished 

 merely by the presence of the product. The eggs pass into the body- 

 cavity and from here into the operculum, where they are fertilized and 

 a capsule is secreted ; from here they pass out through the opening of 

 the operculum and are placed in the mid-dorsal furrow. The oper- 

 culum does not serve for a brood-pouch as does that of S. spirillum." 

 She probably refers to the species studied by Pagenstecher in 1862, 

 which he erroneously identified as S. spirillum, to which Quatrefages 

 in 1865 gave the name S. pagenstecheri. In the many specimens 

 recently examined, of S. spirillum Linn6 detached from kelp (Lamt- 

 naria) , chains of eggs have been found in the tube. This is supposed 

 to be the species studied by Fewkes in 1885, as S. borealis; the S. 

 spirillum of Agassiz (1866) is S. borealis Daudin = S. spirorbis 

 Linne. 



Saint -Joseph (1894) states that he found in Mera pusilla {Spirorbis 

 pusilloides nom. nov.) not only well-developed embryos in the opercu- 

 lum, but large ova in the first two abdominal segments and spermatozoa 

 in the following ones. In one instance only were spermatogonia and 

 spermatozoa seen (see Addendum) ; but the other features were noted 



