242 GXELEXTEBATA. 



as small vesiculate Jfedusce, with generative organs on the radial 

 canals (Eucojridce, Geryonopsidce, Ae^uoridce). 



Fam. Plumularidae. The hydrothecae of the branched hydroid-st' cks are 

 arranged in single ro\vs ; thuse of the nutritive Polyp have small accessory 

 calyces filled with nemato.-ysts (uernatocalyces). Pluntulariii crixtnta, Lam., 

 Anti'imnliirin iiiiti-nitlnn Lam. 



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

 flask-shaped hydrothecse on opposite sides of the stem. Di/mimi-na pumila L., 

 Xcrtultiritt- itliii-tinu. rvjircsxin/i L. 



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

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

 conical proboscis. Campamdaria Lam. The proliferous individuals are 

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

 short manubrium with four lips, four radial canals, the sr.ire number of 

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

 the inter-radial tentacles are formed. C. {Clytliia) Jolinstoni = -rlulHis Johnst., 

 probably with Eueope variabilis Cls. Olella Per. Les., is distinguished from 

 C:impiinularla by its Medusa. These are flat, disc-shaped Mrdusa with 

 numerous marginal tentacles, but with eight inter-radial vesicles. 0. (licit otoma 

 ~L. = (Campanularia gelatinosa van Ben.), C. genieulata L., Laomedva Lamx. 

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

 L. caliculata Hincks. 



Fam. Aequoridae Medusa? with numerous radial vessels and marginal tentacles. 

 Aequorea Forsk. The Geryonopsidee are allied here. Oct orchis E. Haeck. 

 Tim a. 



(5) Sub-order: Trachymedusce. Medusae 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 

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

 the eight radial canals. Trachynema ciliutum Ggbr. Ilhopaloni-ma vdatum 

 Ggbr., Messina. 



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

 The extended diges'.ive cavity has pouch-like enlargements in place of the 

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

 Cunina allfxccnx <!gbr., Naples. Aegineta 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. Lii-ij>i- Less., with four radial canals, four or eight 

 tentacles and eight vesicles. L. ti t rn /ilnjllu Cham., Indian Ocean. Geri/onia 

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

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

 C. hastata, Nice. 



