POLYCH^TA SEDENTARIA OF THE FIRTH OF FORTH. 639 



its characteristic honeycomb-like reticulum of projecting ridges. The bands of 

 cilia project through this vitelline membrane (fig. 2 h). By proper focussing a 

 bundle of cilia can be seen passing through one of the usually hexagonal meshes 

 of the reticulum. The cilia doubtless pierce the membrane during their growth. 

 In front of the anterior band of cilia the greater part of the surface of the larva 

 is separated by a considerable space from the vitelline membrane, but a median 

 anterior projection, shaped like a truncated cone, extends forwards to the mem- 

 brane in the direction of the longer axis, and from this projection, that is from 

 the apex of the prseoral lobe, a bundle of long stiff sensory hairs projects 

 through the vitelline membrane : these hairs are quite motionless, and are prob- 

 ably cuticular, not protoplasmic like cilia. Between the anterior and posterior 

 rings of cilia is another space between the surface of the embryo and the vitelline 

 membrane. At a later stage the embryo elongates, and the sides of the embryo 

 come into contact with the vitelline membrane, especially at two points on each 

 side, from which two pairs of fascicles of long setae grow out. These setse 

 are directed backwards, and the anterior are much the longer. These bristles 

 represent two pairs of parapodia (fig. 2 c). By the elongation of the embryo 

 the vitelline membrane is brought into closer contact with the embryo, so that 

 the spaces described above are more or less completely eliminated. The 

 cilia have been described as forming rings, but we are not certain that the 

 rings are complete : the anterior band is continuous across the dorsal side, but 

 is formed of a number of tufts, not of a regular series. Apparently the mouth 

 and anus are not yet formed, but a central cavity is seen in optical sections 

 in the hypoblast. Two eye spots of dark pigment are present on the dorsal 

 side in front of the anterior ciliated band. The larva is thus a telotroch. Figs. 

 2 i, 2 j , represent a later stage of the larva. 



Anatomy. — The nephridia and ovaries in this species resemble those of the 

 preceding, but the efferent duct of the nephridium is longer, and its external 

 aperture more dorsal in position. 



Genus Seolecolepis (Blainville), Malmgren. 



Malmgren [Ann. Polych., p. 199) takes this name for a genus, in which he 

 includes the Nerine vulgaris of Johnston and Sars, and N. currata and N. 

 oxycephala of Sars. The name was used by Blainville in 1828 (in Diet. Sci. 

 Nat., t. 57, we presume) for the Lumbricus squamatus of Muller's Zool. Dan., 

 which is possibly identical with Nerine vulgaris, Johnston. We use the name 

 as applied by Malmgren. That author gives no definition of the characters of 

 the genus, and we have not supplied the defect. We can only point out that 

 the chief peculiarity is that the cephalic lobe is somewhat T-shaped, having 



