ON THE BRITISH ANNELIDA. 23S 



the papillary glandules of the proboscis, like their elaborate representatives 

 in the mouth, furuished a fluid for the exclusive purpose of insalivation. 



In the Phyllododdce the biliary intestine begins where the mechanical oeso- 

 phagus ends. Neither a crop nor a gizzard intervenes between these two 

 divisions. It is on this account that the inference, denying to the probos- 

 cidian glandules an exclusively salivary office, is rendered probable. These 

 glandules in reality may supply a fluid, uniting in its chemical agency the 

 twofold properties of the gastric and the salivary. 



The segmentation of the body, exteriorly, is in these ornate worms very 

 deeply marked. This fact determines the degree in which the intestinal 

 canal is segmented. It is curious, however, that the oesophagus should in 

 no case conform in the outline of its structure to that. of the integuments. 

 In no known instance is it sacculated or annulated, like the intestine. This 

 latter division of the canal in these worms is quite moniliform in figure, the 

 contiguous sacculi being divided by an interval of constriction equal in length 

 to themselves. The biliary glandules, which in the PhyllodocidcB are charged 

 with a dark green pigment, are limited in their distribution to the dilated 

 portions of the intestine, and may be^ traced in diminishing numbers to the 

 extreme tail-end of the tube. It is probable that the absence of the charac- 

 teristic colour in the biliary layer of the intestine may depend in some way 

 upon entire absence of all red pigment from the blood. Such facts as these, 

 bearing to each other an evident though unresolved connection, suggest the 

 conclusion that all local pigmentary accumulations, whether occurring in 

 glandular organs or integumentary structures, are mere modifications of the 

 primary pigment matter of the blood. The blood in the Phyllodocid<s being 

 devoid of all colour, it is accordingly difficult to conceive the source whence 

 the materials of colour may be drawn by the biliary organs. In confirmation 

 of this doctrine the instance of Phyllodoce viridis may be mentioned. All 

 the structures in the body in this worm are strongly tinged with a grass- 

 green colour, and that probably because the blood is densely charged with 

 this pigment. 



The Syllidce (Plate XI. fig. 59) are proboscidian worms, and no known 

 species presents an exception to this rule, — in some they occur as minute 

 transparent bodies on the inside of the orifice of the proboscis. This organ 

 in S. prolifera (fig. 59) exhibits four of these little corneous formations (fig. 

 59a); they are crenated at their distal end. In S.armillaris these piercing 

 instruments are replaced by a single cup-shaped organ, of the mechanism of 

 whose action it is difficult to form a correct conception. It is placed on the 

 superior edge of the terminal orifice of the proboscis ; the edges of this orifice 

 being fringed with fleshy papillae, which are obviously, from their situation, 

 the seat of exaggerated tactile sensibility. In other species there is no corneous 

 formation of any sort superadded to the proboscis. These Annelids are gene- 

 rally found creeping over the surface of algaceous plants. From the absence 

 of any structure bearing the semblance of browsing organs, or mechanical 

 additions of any description to the proboscis calculated to cut and masticate 

 vegetable substances, taken in conjunction with the circumstances under 

 which these worms are commonly discovered, they may be classed \\ith con- 

 fidence among the herbivorous Annelida. This conclusion is supported by 

 the anatomical proofs derived from the character of the digestivecanal. 



In the Syllidce the proboscis (fig. 59 6) is capable of extrusion to a con- 

 siderable distance beyond the mouth. Unlike that of nearly all other Anne- 

 lids, it is quite smooth and destitute of all traces of parietal glandules. In this 

 genus the papillary glands are transferred to the walls of the oesophagus 

 (fig. 59 c). They may be readily seen projecting beyond the plane of the ex- 



