298 MR. H. N. MOSELEY ON DEEP-SEA ACTINIARIA 



The animal on retracting the protruded parts of the mouth became of a simple cylin- 

 drical form with the disk concave. 



The absence of tubercles on the costse, and tbeir presence on the calicinal margin 

 only, and the extreme shortness of the tentacles, places this Minyad near the genus 

 Nautactls. It differs, however, from the Nautactis olwacea *, as described by MM. 

 Milne-Edwards and Haime, in having 24 costag instead of 22, and in the nature of the 

 tentacles, which in N. ollvacea are tuberculated, simple and very small towards the 

 centre, and multilobate towards the circumference of the disk. 



Lakval Minyad. (Plate XLV. fig. 3.) 



On Nov. 2, 1874, off the Philippines, in lat. 12° 43' N., long. 122° 10' E., a larval 

 Minyad was obtained Avith the towing-net from the surface. 



This larva was about 1*5 millim. in height. The body was ciliated over its entire outer 

 surface. No tentacles were as yet formed in the larva, but the mouth was maintained 

 everted, and showed six distinctly marked lobes. Six primary mesenteries were well 

 developed, and six intermediate secondary just indicated. Upon the larva being 

 compressed, a single pair of mesenterial filaments was emitted from its mouth. The 

 filaments and the ectoderm were crowded with simple, elongate, ovoid nematocysts. 



Oceanactis, gen. nov. 

 Characters. — Body transparent in the contracted condition, smooth and spherical in 

 shape ; when expanded hemispherical, provided with rounded costal ridges and a single 

 row of costal tubercles. Tentacles simple, elongate, conical, and in two rows. Base 

 very small, entirely invisible in the contracted condition, with an aperture in the centre 

 communicating with the body-cavity. 



Oceanactis bhodactyltjs, n. sp. (Plate XLY. fig. 4.) 

 On July 10th, 1874, the trawl used in 700 fathoms in lat. 37° 36' S., long. 179° 24' E., 

 about forty miles off New Zealand, came up full of a tenacious blue clay. In the clay 

 were found two Actinias in a contracted condition. When thus contracted they were 

 nearly spherical, with a tense and perfectly smooth transparent external tunic, through 

 which the mesenterial septa were plainly visible, as also the ovaries and the stomach- 

 wall. No trace of any base or basal aperture could be made out in this condition of the 

 animals. The oral orifice appeared as a small, slightly protuberant reddish cone. Each 

 animal on the whole looked not unlike a small onion. Placed in fresh water for the 

 night the animals expanded to the form shown in the accompanying figru*e. 



The body of the animal in the expanded condition is nearly hemispherical. The upper 

 part of the stomach is protruded as a semitransparent cone beyond the circle of ten- 

 tacles. There are twenty mesenterial septa, the spaces between which rise up as rounded 

 ridges or costse on the wall of the expanded body. Ten of these bear, just above the 

 origin of the tentacles, rounded prominent tubercles. 



* ' Histoire Naturello des Coralliaires,' Milne-Edwards et J. Haime, tome i. p. 230. 



