REPORT ON THE ACTINIA RIA. 25 



Habitat. — {a) Station 311, January 11, 1876; depth, 245 fathoms. Three speci- 

 mens. (6) Station 320, July 14, 1876 ; depth, 600 fathoms. One specimen. 



Dimensions. — Length of the contracted animal, 2 "5- 3 '2 cm. ; breadth, 2 '5-3 '5. 



At first I was inclined to refer the three specimens from Station 311, which were 

 seated on MoUuscan shells, and the single specimen from Station 320, to Phellia 

 pectinata ; for they possessed the characteristic appearance of the body-wall, resembling 

 the tunic of CynthicB, while the upper indrawn part of the wall presented the ridged 

 surface which has been already figured. I was, however, persuaded to a closer study 

 by observing some points of divergence in the structure of the peripheral region of 

 the body-wall. The transverse and longitudinal ridges are wanting, instead of which 

 occur knobs, resembling those of Cereus spinosus ; these start with a broad base, and 

 terminate in a slightly truncated tip ; they are distinguished from the body-wall, which 

 is nearly white, by a brownish tint, and may amount to 200 in number, distributed 

 more abundantly on the upper than on the lower regions of the body-wall. The upper 

 knobs are as much as 0"25 cm. long, and are more strongly developed than the rest; 

 they become gradually smaller below, anel finally appear only as fine grains. Such an 

 arrangement of the knobs in series, as exists in Bimodes, does not occur. 



The mesogioea of the body- wall is so extraordinarily stiff as to cause some trouble, 

 before good sections of the sphincter can be efi"eeted. The latter is essentially constituted 

 as in Phellia piectiiiata, so that refevence to the description given under that species is 

 sufiicient. In position it is considerably nearer to the ectoderm than to the endoderm. 



The oral disc and stomatodseum are of a brownish violet (partially altered in the 

 alcohol), the former lighter in tint than the latter. On the stomatoda^um the two 

 siphonogiyphes, which are not pigmented, and are consequently of a whitish yellow, 

 strike the eye on opening the animal as two broad, sharply-marked, stripes. They are 

 only distinguished from their surroundings by this diff"ereuce of colour, since they are 

 Hush with the rest of the stomatodseum. They are crossed by transverse folds regularly 

 arrano-ed, Avhich are continuous over the rest of the stomatoda3um. Further, the 

 stomatodseal cone is hardly expressed at all, and the longitudinal furrow.'^, whicli so 

 commonly run parallel to the siphonogiyphes between the mesenterial insertions, arc 

 wanting. 



For the characterisation of the species the condition of the musculature of the oral 

 disc is also of importance ; it exhilnts two methods of formation. In the one case it is 

 purely ectodermal and markedly pleated, the pleats I'unuing parallel to one another, 

 and oulj' slightly arborescent (PL 11. fig. 9). At other points (fig. 8) the arboresceuce 

 is very considerable, the individual branches anastomosing with one another ; the 

 musculature thus becomes partly mcsogloeal, and a ver}' obvious and stout muscle- 

 layer arises. The muscle-fibres are here, as in the sphincter and the powerfully 

 developed lamiuai of the retractors, of exceptional thickness. 



(ZOOL. CnALL. E.KP. — PART L.X.XllI. — 1888.) DdtUl 4 



