426 Prof. M'Intosh on the 



In tlie anterior region the dorsal lamellae, as usually seen 

 from the dorsum, are larger than the inferior and somewhat 

 more translucent. In front of the insertion of the bristles 

 is a pad of cuticle and hypoderm. \yhile the inferior 

 lamella is smaller, its bristles are longer. The lamellae of 

 the ninth body-segment are very prominent, and between 

 them and the pads in front the bristles project. In the 

 posterior segments each forms a large fan-shaped process 

 extending from the body-wall, and a pad at the base bears 

 the hooks. In addition to the lamella there is a small conical 

 hypodermic papilla (which, in the living animal, at first sight 

 resembles the point of a spine) at the inner side of each row 

 of hooks. Toward the tail they assume a filiform appear- 

 ance, and in section their structure approaches that of the 

 caudal cirri. 



In minute structure the hypoderm very much resembles 

 the cutis of the Nemerteaus, presenting under pressure a 

 series of flask-shaped cells or glands, from which the contents 

 often escape in the form of clear and granular globules. 

 Moreover, it contains a vast number of bacillary cells or 

 glands, the structures being slightly acted on by water, which 

 are found abundantly in the snout, cover for the most part 

 the entire anterior region, and besides being continuous 

 along the sides in the posterior region, form a band across 

 the body behind each row of hooks. They are very con- 

 spicuous in the caudal region. 



Most of the so-called granular glands or cells, indeed, 

 seem to be bacillary cells. The appearance of the latter 

 varies according to position, for when seen on end each 

 appears to be granular, while a lateral view exhibits the rod- 

 like bacillary bodies. These organs are soon destroyed by 

 pressure and are not well seen in most spirit-preparations. 

 They are best observed in living or fresh animals in sea- 

 water, are common in the Spionidse, and are termed by 

 M. Clapar^de bacilliparous glands. AVhen pressure is made 

 on the posterior end of a fresh specimen the enormous 

 numbers of these cells and bodies is remarkable, and the 

 latter often form stellate groups on piercing the cuticle. 

 Many of the cells contain pigment and others a large clear 

 globule. 



In the tentacles are a number of small but distinctly 

 granular hypodermic cells, which form rows in the contracted 

 state between the rugae of the cuticle, at the base, below the 

 papillose margin. 



A hypodermic process (like a short conical tentacle) 



