A COLLECTION OF HYDI^OIDS. 



287 



in length and 19*5 /u in breadth. The small neniatocysts, 

 measuring lO'Ofi in length and S'Ofi in breadth, are abundant 

 on the moniliform tentacles (fig. 16, s-.n.). 



The moniliform aspect of the tentacles is due to the presence 

 of thickened rings or patches of ectoderm. The axis of 

 septate endoderm takes no part in the production of the 

 swellings, and, in fact, it seems sometimes to be somewhat 

 constricted by them. The terminal swelling is more or less 

 spherical, but it is much smaller than the capitulum of an oral 



Text-fig. 3. 



Endudeniuilcanals iu Asyncoryne ryniensis, sp.n. A x 70 

 5 X 150 ; C X 40 ; Z> X 80. 



tentacle, and it appears never to possess large nematocysts. 

 The small nematocysts tend to be crowded on the summits of 

 the patches and thickened rings. 



The endoderm of the hydranth consists of elongated cells 

 with large vacuoles, and between them are Avedged glandular 

 cells igLc), which stain deeply, and contain granules or 

 numerous small vacuoles. 



Cross-sections of the ccenosarc of the hydrorhiza mav, in 

 certain parts, exhibit two, three, or four tubes of endoderm, 

 surrounded by a common ectoderm. This condition is shown 

 in text-fig. 3, ^, as it occurred in a branch of the hydrorhiza 



