242 CCELENTERATA. 



as small vesiculate Medusce, with generative organs on the radial 

 canals (Eucopidce, Geryonopsidce, Aequoridce). 



Fam. Plumularidae. The hydrothecae of the branched hydroid-stocks are 

 arranged in single rows ; those of the nutritive Polyp have small accessory 

 calyces rilled with nemntocysts (nematocalyces). Plumularia cristata Lam., 

 Antennularia antcnnina Lam. 



Fam. Sertularidae. Branched Polyp stocks, the Polyps of which project in 

 flask-shaped hydrothecas on opposite sides of the stem. Dynamena pumila L., 

 Sertularia abietliia, cupressina L. 



Fam. Campanularidae-Eucopidae. The cup-shaped hydrothecas are placed at 

 the end of ringed stalks. The Polyps possess a circle of tentacles below their 

 conical proboscis. Campanularia Lam. The proliferous individuals are 

 situated on the branches and give rise to free Medusce, bell-shaped, with a 

 short manubrium with four lips, four radial canals, the srire number of 

 marginal tentacles, and eight inter- radial marginal vesicles. After separation 

 the inter-radial tentacles are formed. C. ( Clytliia') Jolinstoni = volulilis Johnst., 

 probably with Eticope variabills Cls. Obelia Per. Les., is distinguished from 

 Campanularia by its Medusce. These are flat, disc-shaped Medusce with 

 numerous marginal tentacles, but with eight inter-radial vesicles. 0. dicliotoma 

 L. = (Campanularia gelatinosa van Ben.), C. geniculata L., Laomedea Lamx. 

 The generative buds remain sessile in the hydrotheca of the proliferous polyps. 

 L. caliculata Hincks. 



Fam. Aequoridae. Medusce with numerous radial vessels and mat ginal tentacles. 

 Aeqiwrea Forsk. The Qeryonopsidce are allied here. Octorckls E. Haeck. 

 Tim a. 



(5) Sub-order : Tr achy medusae. Medusce with firm, gelatinous 

 umbrella, supported by cartilaginous ridges with stiff tentacles filled 

 with solid rows of cells ; these may be confined to the young stage 

 (larvae of Geryonidce). Development by metamorphosis without 

 hydroid asexual individual. 



Fam. Trachyneinidae, with stiff marginal tentacles, which are scarcely capable 

 of motion. The genital organs are developed on vesicle-like swellings of 

 the eight radial canals. Tracliynema cillatum Ggbr. Rhopalonema relatum 

 Ggbr., Messina. 



Fam. Aeginidae. The hard cartilaginous umbrella has a flat, discoid shape. 

 The extended digestive cavity has pouch-like enlargements in place of the 

 radial vessels. The circular vessel is usually reduced to a row of cells. 

 Cunina albescent Ggbr., Naples. Aegincta flavescens Ggbr. 



Fam. Geryonidse. Umbrella with cartilaginous mantle ridges and four or six 

 hollow tube-shaped marginal tentacles. The manubrium is long, cylindrical, 

 or conical, with a proboscis-like oral portion, and four or six canals which lead 

 into the radial canal. The generative organs lie on the radial canals ; eight or 

 twelve marginal vesicles. Liriope Less. , with four radial canals, four or eight 

 tentacles and eight vesicles. L. tetraphylla Cham., Indian Ocean. Geryonia 

 Per. Les., with six radial canals without lingual cone. G. umbella E. HaecK. , 

 Cannarina E. Haeck., with six radial canals and a lingual cone, E. Haeck, 

 C. h&stata, Nice. 



