AND PELAGIC SURFACE-SWIMMING SPECIES. 297 



The tentacles, 20 in number, are simple, elongate, conical in shape, and disposed in 

 two series. The tentacles of the outer series are the larger, and correspond to those 

 costas which bear tubercles. The inner are in connexion with the intermediate costte, 

 and arise from the edge of the disk just internally to the larger tentacles. At the aboral 

 pole of the animal is a small aperture, surrounded by a small circular area with tumid 

 folds representing the base. This aperture is in direct communication with the body- 

 cavity, for one of the ovaries became protruded through it Avithout any violence having 

 been used. There is hence no separate chamber for the air-vesicle as in Minyas, but the 

 condition is like that in Peachia. The general transparent appearance of the animal, 

 however, and absence of base sufficient for attachment in an animal of this short hemi- 

 spherical shape, point to its being a free-floating and not a deep-sea form. Perhaps the 

 condition is here somewhat as in Nautactis, where the base may be reversed, the air 

 extruded, and the body attached from time to time to floating bodies (M.-Ed. & H. I. c. 

 p. 230). The body of the animal is transparent and bluish coloured, with a slight 

 dusting of light red on the costae. The base is reel. The costal tubercles are transparent 

 and marked with red, especially at their lines of origin from the costae. The tentacles 

 are of the same light red colour and somewhat transparent. The margin of the mouth, 

 which presents ten slight indentations, is also tinged with red. In the contracted con- 

 dition of the animal the ovaries show through the body-wall as yellow bodies near the 

 aboral pole. The stomach also is seen in the same manner as a transparent whitish 

 cylinder. The tentacles and tubercles are full of nematocysts of the common elongate 

 form, and about - 04 to "05 millim. in length. 



The animal apparently belongs to the group of the Minyadinae (M.-Edwards & Haime, 

 I. c. tome i. p. 227), but does not seem to come exactly within either of the three genera of 

 that subfamily, viz. Minyas, Plotactis, or Nautactis. Erom Naulactis it is distinguished 

 by the simplicity of its tentacles, from JPlotactis by its single row of costal tubercles, and 

 from Minyas by not possessing a series of tubercles on each costa. It is further 

 distinguished from all three genera by the perforation of its base. 



Subfamily Actinin^. 

 Actinia abtssicola, sp. n. (Plate XLV. fig. 5.) 



This animal, found adherent to the stem of a species of Mopsea, as depicted, is drawn 

 out and elongated in a direction transverse to the central axis of the body in relation 

 with the slender cylindrical form of its support. 



The adherent surface of the base is extremely elongated, and of the same width 

 throughout, and is closely applied to the Mopsea-stem lapping round it, the region of 

 junction of the opposite edges being marked by a perfectly straight line. Along this 

 line of union the two edges are somewhat coalescent, but separable without the appli- 

 cation of much force. At either end of the elongated base the body swells out into 

 rounded masses, narrowed at the extremities, and evidently representing the fleshy 

 lobes present around the bases of normal Actinias, which are thrown into this form in 

 this instance by the extreme contraction and elongation of the attaching surface. "Within 



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