242 C<ELENTERATA. 



as small vesiculate Medusce, with generative organs on the radial 

 canals (Eucopidce, Geri/onopsidce, Aecjuoridce}. 



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

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

 calyces filled with nematocysts (nematocalyces). Plumulari-a crixtiitti. Lam., 

 Antenimlarla a/itcnn-ina Lam. 



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

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

 Sertularia abietiiM, i-ujirexxiiia L. 



Fam. Campanularidse Eucopidae. The cup-shaped hydrothecse 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 Medusa, bell-shaped, with a 

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

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

 the inter-radial tentacles are formed. C. ( Clyth ia~) Joli iixtoni = coluMlis Johnst., 

 probably with Europe rtiriabilis Cls. Obeli a Per. Les., is distinguished from 

 Cam/pauularia by its fl/eduxee. These are flat, disc-shaped Me-duxa? with 

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

 L. =(Cfamj)(tnnl(iri(i gelatincma van Ben.), C. geniculata L., Ldomedea Lamx. 

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

 L. call c ill at a Hincks. 



Fam. Aequoridse. Jf edit aw with numerous radial vessels and marginal tentacles. 

 Aequorea Forsk. The Geryonopsidce are allied here. Octorchis E. Haeck. 

 Tima. 



(5) Sub-order : Trachymedusce. 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. Trachynemidae, with stiff marginal tentacles, which are scarcely capable 

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

 the eight radial canals. Trachynema eiliatunt Ggbr. RTiopalonema 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 albescc.its Ggbr., Naples. Aegineta flavescens Ggbr. 



Fam. Geryonidae. 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. tetraplvylla Cham., Indian Ocean. Geryonia 

 Per. Les., with six radial canals without lingual cone. G. umMla E. Haeck., 

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

 (\ hantata, Nice. 



