THIO ANATOMY OF SGALIBREGMA INFLATUM. 249 



are spindle-sliapedj and taper gradually from about the 

 middle, where they are thickest, to their very fine-pointed 

 ends. They are sometimes straight, but more usually are 

 somewhat curved, sinuous, or twisted (fig. 11). These pecu- 

 liar glands are not strictly confined to the cirri. In four of 

 the specimens which have been cut into sections there is, 

 just below each of the neuropodia of two or three of the 

 anterior segments (ranging from the third to the sixth), a 

 collection (or sometimes two) of deeply staining cells in the 

 epidermis. Each of these cells contains a bundle of rods 

 exactly like those above described from the parapodial 

 glands. In two or three cases there is a small bundle of 

 these rod-forming cells, either in or immediately below the 

 epidermis, near the terminal portion of the first or second 

 nephridium. Claparede (1868, p, 15) has noticed the con- 

 nection of similar rod-containing cells with the excretory 

 pores in certain Hesionids. 



Rod-secreting glands similar to those of Scalibregma 

 are known to occur in the skin and subepidermal tissues of 

 a large number of Polychaetse. Claparede has described 

 almost indentical structures (" bacilliparous follicles") in the 

 cirri of Phyllodoce, sp. (1863, pi. xi, figs. 19, 20), in 

 papillfB on the neuropodia of Aricia foetida (1868, pi. xx, 

 figs. 2 5, 2 C], in Nereis cirratulus, especially in the 

 parapodia and their appendices (1868, pi. xxiv, fig. 1 L). 

 A very useful series of figures of these glands, some original 

 and others collected from various authors, is given by Eisig 

 (1887, pi. xxxvii). 



6. Skt.t^ (PI. 13, fig. 9, and PI. 15, figs. 25, 26). 



Both Rathke and Sars described the setae of Scalibregma 

 as simple, fine, capillary bristles, and they quite overlooked 

 the peculiar fui-cate setas which are present in both divisions 

 of the parapodia throughout the body. Hansen (1882, p. 34) 

 first observed these curious setae in the ventral fascicles of 

 S. (?) abyssorum, S. (?) parvum, and in §. inflatum. 



