CHARACTERISTIC DEEP-SEA TYPES. ACALEPHS. 



137 



is still problematical, surrounding the branch where they occur 

 like minute sponges. They are found to consist of a multitude 

 of flask-shaped receptacles. 



The genus Cladocarpus was established by Allman for a re- 

 markable plimmlarian obtained in the eastern part of the North 

 Atlantic during one of the expeditions of the " Porcupine." 

 Cladocarpus jjaradisea (Fig. 436) j a beautiful species, very 

 striking from its deep and widely separated hydrothecae, was 

 dredged off Tennessee Reef, and off the Samboes, from 174 

 fathoms. 



Hippurella is a genus founded by Allman for hydroids in 

 which the basal ends of the branches carry normal pinnae, while 

 the outer end of the same bear verticillately arranged ribs modi- 

 fied for sheltering the sexual bodies. Hippurella annulata 

 grows in tufts, numerous undivided stems springing from a com- 

 mon base. (Fig. 437.) It is of a rather rigid habit; it was 

 dredged off Pacific Reef, from 283 fathoms. 



In Callicarpa we have whole branches specialized and modified 

 for the protection of the sexual bodies. In Callicarpa gracilis 

 (Fig. 438) the gonosome closely resembles a spike of wheat, and 

 springs by a short peduncle immediately from 

 the main stem. (Fig. 439.) 



The most important of the family of Plumu- 

 laridae devoid of movable nematophores is Pleu- 

 rocarpa, dredged from the neighborhood of the 

 island of St. Vincent in 95 fathoms. In the 

 single known specimen the gonosome (Fig. 440) 

 certainly is the most extraordinary modifica- 

 tion of the branch serving as a protection 

 for the sexual bodies thus far found among 



O 



plumularians. The basket - shaped structures 

 called corbulae, which serve the same purpose 

 in other genera, are, as Allman has shown, 

 modified pinnae, and not, as in Hippurella, 

 Callicarpa, and Pleurocarpa, a branch or por- 

 tion of a branch bearing pinnae modified to pieurocarpa ramo- 

 become specialized bodies with the form of cor- ^ magnified. 



, , (Fewkes.) 



bulae. 



