52 THE OCEANIC HYDROZOA. 



Fam. PRAYIDiE. 



Genus PRAY A {Be Blaimille). 



The pi'oximal and distal nectocalyces are similar, and of a gelatinous texture. The 

 hydroecia of both the nectocalyces are open, groove-like, and applied together so as to form 

 a tube in which the upper part of the coenosarc lies. The hydrophyllia are thick, renifc rm, 

 and gelatinous. 



Praya diphyes? pi. Ill, fig. 3 ; and Pi. XII, fig. 5. 



The body figured in PL III, fig. 3, 3 a, is thus described in my notes : 

 An ovate, reniform, gelatinous mass, presenting a small, hemispherical cavity at its lesser 

 extremity, and widely excavated below. From the centre of this inferior excavation depended 

 a twisted tubular cord (coenosarc), surrounded in its upper part by a mass of nascent organs. 

 The cord expanded into a broad muscular band at its point of attachment, and through 

 the centre of this ran a narrow canal, which appeared to connect the cavity of the cord with 

 a narrow, thick-walled cavity (somatocyst), extending along the roof of the inferior excavation 

 from one extremity to the other. From this cavity a small canal was given off to tlie 

 hemispherical natatorial cavity (nectosac), and on reaching it divided into four canals. 



Length . . . -re i"ch. 



This specimen was taken on the 23d June, 1847, in the Indian Ocean. I obtained 

 another in Torres Straits in 1849, and one more in the South Atlantic in 1850 ; neither of 

 these had any polypites. 



In the last the hemispherical cavity was in active contraction, and the adjacent extremity 

 of the organ was more distinctly bilobed. 



I have little doubt that this fragmentary organism is the same as that described by Uuoy 

 and Gaimard under the name of Bosacea plicata. As Leuckart (Z. N. K., 39) has well 

 pointed out, however, the two species of Rosacea described by the French naturalists are only 

 isolated parts of what in its entire state is known as the genus Praya; and on comparing my 

 figures with the excellent and well-illustrated accounts of this genus which have been 

 recently published by Vogt, Kolliker, Leuckart, and Gegenbaur, I entertain no doubt that my 

 specimens were merely the detached proximal nectocalyces of a Praya. 



Leuckart states, indeed, that he has frequently found Praycs which have lost one 



