133 



Fam. Clavatellidae. Hydranths with simple verticillate ca- 

 pitate tentacles. CTonophores in the form of ambulatory mediisae 

 with undeveloped umbrella and branchinar marginal tentacles. 



Clavatella Hincks (= Eleiitheria Krohn). Hydrocaulus rudimenta!, 

 springing from a creeping filiform hydrorhrza, the whole invested 

 with a chitinous perisarc. Hydrantb elongated with its tentacles in 

 a Single verticil, which siirroiinds the base of a conical hypostorae. 

 Gonophores developed in Clusters on branched peduncles from the 

 body of the hydranth. Rudiraental umbrella not fitted for natation. 

 Manubrium short, conical, destitute of oral appendages ; radiating 

 canals six; marginal tentacles six, bifurcatcd, the outer branch of 

 the bifurcation terminated by a capitulum of large thread-cells, the 

 inner by a claviform enlargement, which carries a suctorial disk of 

 attachment; on ocellns at the root of each tentacle, but no distinet 

 marginal bulbs. 



Gl. prolifera Hincks. 



Fam, Cory morphidae. Ilydrocanlua solitary, destitute of 

 perisarc. Hydranth with a proximal and a distal set of filiform ten- 

 tacles. Gonophores in the form of medusiform planoblasts with four 

 radiating canals and one or more simple marginal tentacles. 



Corymorpha Sars (p. p.). Hydrocaulus emitting towards its 

 proximal extremity tubulär fleshy processes; perisarc replaced by a 

 delicate filmy pellicle. Hydranths flask-shaped, abruptly distinet 

 from the hydrocaulus; poximal tentacles imperfectly contractile, lar- 

 ger them the distal, and arranged in a single verticil near the base 

 of the hydranth, the distal tentacles very contractile, forming several 

 closely approximate alternating verticils round the base of a conical 

 hypostome. Planoblasts borne on branched peduncles which spring 

 from the body of the hydranth between the proximal and distal 

 set of tentacles, with a deep-belled umbrella, a well-developed simple- 

 mouthed manubrium and a single marginal tentacle; each of the 

 radiating canals terminates at the junction with the circular canal 

 in a bulbous expansion without distinet ocellus; one of these bulbs 

 is larger than the other, and from this alone the solitary tentacle 

 is developed. 



C. nutans Sars. 



Halatr actus n.geu. Hydrocaulus surrounded towards its proxi- 

 mal extremity with tubulär fleshy processes. Hydranth abruptly 

 distinet from the hydrocaulus; the proximal set of tentacles in a 

 Single verticil, and larger than the distal, which are scattered or 

 subverticillate round the base of a conical hypostome. Planoblasts 

 sessile, springing from the body of the hydranth between the pro- 

 ximal and distal sets of tentacles; umbrella at the time of libera- 

 tion bell-shaped, with one of the four radiating canals continued 



