AGALMA. 75 



Gpnm AGALMA {Eschschoh). 



Nectocalyces biserial. Branches of the tentacula terminated by involucrate sacculi, with 

 two filaments and a median lobe. 



Agalma breve, pi. VII. 



A. Okenii (?) Eschscholz, 1829. 



A. intermedia (?) Quo}' and Gaimard, 1833. 



To the naked eye this animal appeared hke a prismatic mass of crystal, traversed by a 

 delicate filament, terminated at one extremity by a pink spot, and at the other by an irregular 

 pink mass. The pink spot is the pneumatophore, or float ; the filament, the coenosarc ; the 

 pink mass, the polypites and their appendages ; while the crystalline prism is formed above 

 by the nectocalyces, below by the solid hydrophyllia, which are appended to and embrace the 

 coenosarc. 



The pneumatophore is oval, and measures about ^th of an inch in length. In the first 

 specimen I examined the walls of the organ were of so deep a colour .that all the details of its 

 structure could not be made out ; but in the second, which was somewhat smaller, the 

 pneumatophore was colourless, and the arrangement of its internal parts was easily deter- 

 mined. 



The pneumatocyst appears to be open below ; but however this may be, its cavity does 

 not communicate with that of the coenosarc, for the endoderm, which is reflected upon and 

 closely adheres to its outer Surface, does not stop short of the lips of the aperture, but extends 

 completely over it. It is not tightly stretched over the aperture, but forms a sort of loose, 

 bag-like end, extending far below it. The contents of the pneumatocyst could be readily 

 forced into this sac, and they returned again when the pressure was removed. 



The sac thus formed by the reflected endoderm does not hang loosely and freely in the 

 cavity of the pneumatophore, but is connected with the walls of the latter by a number of 

 vertical, mesentery-like; partitions. These terminate in free arcuated edges opposite the lower 

 end of the reflected endodermal sac. Immediately below the pneumatophore a number of 

 budding nectocalyces, in all stages of development, make their appearance, the youngest being 

 the highest. Of the fully-formed and functionally active nectocalyces, however, there were only 

 five, three on one side, and two on the other. Viewed laterally, these organs appear fusiform, 

 while from above they have a horseshoe shape, in consequence of the deep concavity of their 

 internal edges. Above and below they present a deep and wide groove, whose edges are 

 bounded by well-defined ridges, or rather crests. 



