REPORT ON THE ANT1PATHARIA. 207 



The ectoderm of the stomodseum is considerably folded, and contains a number of hyaline 

 gland cells near the surface, between which are bundles of spindle-shaped cells with 

 deeply-stained nuclei. Between the basal ends of the spindle-shaped cells another row 

 of hyaline gland cells occurs, the base of each cell being imbedded in a thin nervous 

 layer. A few small, oval, granular gland cells may also be distinguished at irregular 

 intervals near the surface of the layer, which are similar to those of Antipathes dichotoma. 



Mesoglcea. — The mesogloea varies from 2 to 5 ^ in thickness, and apparently only 

 differs from that of Antipathes and Antipathetic/, in having frequently a dentate instead 

 of a smooth surface. 



Entoderm. — The entoderm is relatively thick, and consists chiefly of oval hyaline 

 gland cells, between which a number of elongate thread-like cells occur. The surface of 

 the layer is usually occupied by a row of epithelial cells which taper below to a fine 

 thread, but in portions where the entoderm is thinner this row is not distinct. The 

 gland cells do not stain in carmine or hsematoxylin, but frequently appear to contain a 

 reticulate or granular coagulum (PL XV. fig. 3, g). The entodermal surface of the 

 mesoglcea bears a row of circular muscular fibres, which extend from the body-wall, 

 through the peristome, to the tentacles. The surface of the mesogloea is dentate in many 

 parts, and the layer of muscular fibres follows the dentate outline. In horizontal sections 

 the middle portion of each transverse mesentery is seen to be considerably thickened 

 (0"10 to - 18 mm.), and contains two or more rows of gland cells. Those near the 

 surface are hyaline, but others near the base of the layer are filled with a finely granular 

 mass which does not stain. 



The mesenterial filaments are plate-like folds of the free margin of the transverse 

 mesenteries (PL XV. figs. 4, 5). In transverse vertical sections of a zooid each filament 

 is seen to consist of two portions. The rounded and slightly ddated free extremity 

 stains deeply, and has a structure which corresponds precisely with that of the stomodseal 

 ectoderm, whilst the remaining portion of the filament does not stain so deeply, and 

 consists of a median strand of mesogloea clothed on each side by entoderm. The large 

 oval gland cells of the entoderm are very prominent (PL XV. fig. 5, g) and often measure 

 23 x 16 p. 



Parantipathes larix. 



The zooid is relatively more elongate in this species than in any other with which I 

 am acquainted. The tentacles are elongate and slender, and the whole of the zooidal 

 tissues are unusually thin. The body-wall only measures from 64 to 75 /x in thickness. 

 A series of horizontal sections show the variation in the shape of the stomodseum, tne 

 main features of which appear constant. In the upper sections the lumen is slit-like or 

 more rarely oval, and the greatest diameter corresponds with the sagittal axis. Usually 



