92 STYLARIOIDBS PLUMOSA. 



appeared to be a perfect and large example from Lochmaddy, the anus formed a vertical 

 slit nearer the ventral than the dorsal surface, and above it a parasitic crustacean, which 

 unfortunately cannot now be found, was attached by a process. 



The general colour is greyish-brown, darker on the dorsum, paler ventrally. Attached 

 to the longer papilla of the dorsum are numerous grains of sand, and some particles are 

 firmly fixed to the skin between the papillae. In the coarsely papillose region on the 

 dorsum immediately behind the long anterior bristles, mud, Foraminifera, and sand-grains 

 are frequently abundant. In badly preserved examples the cuticle readily separates from 

 the subjacent hypoderm, carrying with it sand-grains and other adherent structures, 

 and leaving acutely conical smooth papillae on the skin beneath. Moreover, such speci- 

 mens show a coarser papillose surface from the swollen condition of the papillae. 



The mouth is a vertical slit, below the palpi, with fleshy lips which slowly open and 

 close in the continuous swallowing of water, and probably also of muddy sand as food, 

 under ordinary conditions. The inner surface of the lips is pale reddish-brown. Rarely 

 a hoof-shaped process with the flat surface pointing ventrally is thrust out, the anterior 

 or dorsal arch having the eight branchiae along its edge, whilst posteriorly are two 

 external lateral processes, two small median below the transverse mouth, and a larger 

 posterior or ventral process. On an eminence in the centre above the mouth are two 

 brown pigment-spots representing the eyes. 



The mouth leads into a cylindrical oesophagus about half an inch long, followed by a 

 somewhat globular crop, then an elongated stomach with firm walls, coloured orange in 

 some forms internally (Claparede), and nearly three-quarters of an inch long. From this 

 the intestine is thrown into many coils supported by a thin mesentery, and from the mass 

 the gut escapes on a level with the stomach and passes nearly straight backward, and by- 

 and-by in the median line, to the tip of the tail. The crop has a translucent wall studded 

 with single cells, groups of large nucleated cells, and caudate cells. The glands of the 

 stomach are circular. 



The intestine contains coarse sand-grains, sponge-spicules, fragments of the spines 

 of Spatangus, Foraminifers, Radiolarians, elliptical bodies like spores, fragments of algae, 

 and other organic debris in mud. 



The coelom in this and allied forms (S. monilifer) presents behind the stomach a dark 

 pyriform glandular tube, which adheres by its blind end to this organ. It has a pale 

 muscular and vascular coat externally, and internally a coat of intensely black cells. It 

 passes forward to the snout, where Otto describes an aperture. Delle Chiaje termed this 

 organ " bourse-gastro-oesophagienne," and Otto a second oesophagus. Max Miiller 

 thought it was a blind vessel, and so did Costa. It is the heart and heart-body. 



Two symmetrical white tubular glands (nephridia) also are present, and each 

 terminates in a cul-de-sac on the coat of the stomach, while in front they are continued to 

 the snout. They are filled with cells containing spherical bodies— it may be oxalate of 

 lime. Kolliker thought that similar structures in Flabelligera resembled the kidneys of 

 Gastropods. They are probably excretory and open by pores on the snout in Siphono- 

 stoma (Otto and Claparede). The two whitish nephridia were crowded in June with 

 minute granules and innumerable spherules of opaque white oily bodies, apparently 

 somewhat granular. The nephridiopores are quite at the anterior end. 



