REPORT ON THE ANTIPATHARIA. 201 



hyaline gland cells are situated in the depressions between adjoining rugae, and never 

 project beyond the batteries of nematocysts. On this account the arrangement of the 

 ectoderm cells in this species has a close resemblance to that found in Leiopathes 

 glaberrima (PI. XY. fig. 3). 



In all the specimens examined by means of horizontal sections, the stomodasum was 

 found to be relatively small. The portion contained within the oral cone is about 

 - 22 mm. long and 0"15 mm. broad. It opens into the ccelenteron by a funnel- 

 shaped aperture, the lumen of which is entirely occupied by branched mesenterial 

 filaments. 



The entoderm is not very rich in gland cells, and in this respect presents a marked 

 contrast to that of Antipathella subpinnata. It appears to consist chiefly of elongate, 

 ribbon-like, epithelial cells, each with a large round nucleus. Each epithelial cell 

 extends from the surface of the layer to near the base, and possibly may be continued 

 basally into a short contractile filament, as in Actiniaria. In portions of the entoderm 

 containing gland cells, the epithelial cells between them become constricted towards the 

 centre, and thus present a dilation at each extremity. Sexual cells were not observed in 

 all the specimens, but in a few, isolated ova were contained within the transverse 

 mesenteries near their point of union with the lateral body-wall. 



Antipathella assimilis. 



In this species the structure of the ectoderm and entoderm is similar to those of 

 Antipathella minor, but the batteries of nematocysts do not taper so rapidly towards 

 the base. The mouth is slit-like, but a short distance beneath it the lumen of the 

 stomodaeum becomes widely oval. The inner aperture is funnel-shaped, but the portion 

 of its circumference corresponding to each sagittal tentacle, i.e., between the two pairs 

 of directive mesenteries, is not continued to so low a level as the other portions. 

 Laterally the stomodasum is continued on each side as a slightly-curved plate, which is 

 fused with a transverse mesentery and stretches across from a directive mesentery at one 

 end of the body axis to its fellow at the opposite extremity. 



Testis. — All the specimens observed contained a number of spermatic capsules 

 imbedded within the transverse mesenteries. They have usually an oval outline, the 

 largest observed measuring 0'224 mm. x 0*159 mm. Around the periphery of each 

 capsule a number of germinal cells are to be observed, from which the spermatozoa are 

 derived. These cells are distinctly larger than any of the others, and each contains a 

 large nucleus which stains deeply. In the younger capsules the inner portion is filled 

 with cells in various stages of division, and centrally with young spermatozoa. With 

 an increase in size a lumen appears within the capsule, which is usually situated some- 

 what excentrically. In such cases the flagella of the spermatozoa may be recognised as 



(ZOOL. CHALL. ESP. PART LXXX. 1889.) Llll 26 



