TSE ANATOIVIT OF SCALIBREGMA INFLATtTM. 289 



or less areiiicoHfonn, while the latter is magg'ot-like and 

 tapers only slightly at each end. The most obvious external 

 difference is found on examining the parapodia. In S. in- 

 flatum the parapodia from the fifteenth segment to the 

 posterior end project outwards some distance from the body, 

 forming vertical laminae bearing dorsal and ventral ciri-i. 

 Each of the parapodia of E. crass a is foimied by two mam- 

 millge which arise separately from the body-wall and bear 

 the setae; cirri are absent. There are also anal cirri in S. 

 in f latum, but none in E. crassa. 



The gills of these two Annelids are closely similar. In 

 Oei'sted's description of E. crassa it is stated that gills are 

 found in the six anterior segments, and Johnston states that 

 they are "confined to the first six segments." 



Theel (1879) finds only four pairs of gills. In each of the 

 three specimens in my possession (two from the coast of 

 Sweden and one obtained off Nova Scotia) I find only four 

 pairs of gills situated in the second to fifth chfctigerous seg- 

 ments, thus exactly agreeing in number and position with 

 those of Scali bregma. The first gill of my specimens of 

 E. crassa is small, and the fourth is the largest. It is 

 scarcely probable that any other gills would have been 

 formed in these specimens, which are about 80 mm. long and 

 practically mature, as determined by an examination of the 

 sexual products in the ctclomic fiuid. There is, therefore, 

 some difference of ojiinion with regard to the number of gills 

 present in Kumenia crassa. It will be noted that John- 

 ston does not definitely state that there are six pairs. I 

 have been unable to procure a speciinen bearing more than 

 four pairs of gills, and though inclining to the opinion that 

 this is the normal number of branchiae, I cannot settle this 

 question definitely until a much larger number of specimens 

 is available for examination.^ 



' Cunningliam and Kaniage (1888, p. 655, and j)!. 42, fig. IS) describe and 

 figure a specimen named E. crassa, dredged in the Firtli of Fortli, wliicli 

 differs in several respects from specimens described by other authors. The 

 parapodia of their specimen are lamelliform, project prominently from tiie 



