SCTPHOZOA 



127 



Aey to the genera of Liicernariidae here described : 



tti Adhesive pads absent 1. Lucernaeia 



O2 Adhesive pads present. 



&i Stalk quadrate 2. Haliclystus 



hz Stalk cylindrical .3. Halimocyathus 



1. LuCERNARiA 0. F. Mlillcr. Marginal adhesive pads absent; stalk 

 cylindrical: 8 species, 1 American. 



L. quadricornis Miill. Height 7 cm.; diameter 5 cm.; color green, 

 gray, or reddish; tentacles on each lobe 100 or more: Cape Cod to 

 Greenland; Europe. 



2. Haliclystus Clark. Eight 

 marginal adhesive pads between 

 the lobes; stalk quadrate: 6 spe- 

 cies, 2 American. 



H. auricula Clark (Fig. 209). 

 Height and diameter 3 cm.; color 

 variable; tentacles on each lobe 

 100 or more: Cape Cod to Green- 

 land; Europe; Alaska. 



H. salpinx Clark. Height 20 

 mm.; diameter 25 mm.; tentacles 

 slender, about 70 on each lobe; 

 marginal pads very large and as 

 long as the tentacles: Cape Cod to 

 Greenland; Adriatic Sea. 



3. Halimocyathus Clark. Marginal adhesive pads present; 4 

 gastrogenital pockets present in subumbrella wall of the gastrovascular 

 pouches; stalk cylindrical: 2 species. 



H. lagena (Haeekel). Height 3 cm.; diameter 7 mm.; tentacles on 

 each lobe 70: Cape Cod to Greenland; rare; Europe. 



Haliclystus auricula (Mayer). 



Order 2. CORONATAE. 



Medusa with a constriction about its middle; margin in most cases 

 with 16 lobes, long tentacles and rhopalia: 5 families and 27 species, 

 which are usually found in the open ocean. 



Family 1. PERIPHYLLIDAE. 



Marginal lobes 16; tentacles 4 or more; rhopalia 4: 4 genera and 

 8 species. 



Periphylla Steenstrup. Twelve tentacles; body conical; 4 deep 

 subgenital pockets (funnels) ; gonads horseshoe-shaped : 3 species. 



