REPORT ON THE XENIIDAE COLLECTED BY DR WILLEY. 515 



numerous on the inner faces of the tentacles and pinnules. By reflected light the 

 spicules are whitish or very slightly yellow. By transmitted light some of the spicules 

 are almost colourless but the majority have a moderately strong reddish-brown colour. 

 The spicules are oval discs OIQ mm. — '018 mm. in length and '01 mm. — 014 mm. broad. 



The greater part of the colony is yellow in colour, but those parts which have 

 been closely pressed together and partly protected from the action of the spirit are 

 reddish-brown in coloui-. The label on the bottle indicates that this brown colour 

 predominated in life. 



Ova are present in considerable numbers on the edges of the ventral and lateral 

 mesenteries of many of the larger coelentera. The largest oya, which are somewhat 

 oval in shape, are 'o mm. x "6 mm. in diameter (Fig. 13). These are probably mature 

 ova. The spherical or oval nucleus is Oo mm. to '07 mm. in diameter and tlie exceedingly 

 fine and close network which it contains stains deeply with haemato.xylin, safranin, &c. 

 In each nucleus there are about 15 to 20 spherical very deeply staining bodies about 

 iifi in diameter, and a larger number of similar but much smaller bodies about Ifj. in 

 diameter. The nucleus is situated near the edge or circumference of the ovum. A 

 germinal spot is not present in large ova but is very well marked in young ova 

 until they attain a diameter of about "12 mm. In ova of this size and in younger 

 ones the germinal vesicle and germinal spot are quite typical, but in ova gi-eater 

 than '12 mm. in diameter the germinal spot is either very indistinct or quite absent 

 and the nucleus has assumed the appearance and structure of the nucleus of the 

 ripe ovum described above. The protoplasm of the peripheral part of the ovum is 

 finely granular and devoid of yolk granules, which are however present in large 

 quantity in the central part of the ovum. In sections of preserved ova, the yolk 

 substance of which has been dissolved out, the protoplasm of the inner portion 

 contains numerous more or less spherical cavities which in life contained the yolk 

 spherules. This portion of the ovum presents a reticulate appearance as shown in the 

 figure (Fig. 13), the protoplasmic strands are granular but the granules are not ver}' 

 obvious except in the peripheral portion of the inner or yolk-containmg protoplasm, 

 where there are several small but deeply staining granules. The surface of the ovum 

 is depressed in the region of the germinal vesicle. These ova are rather larger than 

 those of Alcyonium digitatum but in other respects resemble them closely (cf Hickson, 

 1895, p. 377, and Figs. 40, 41). 



The stomodaeum of the fully developed polyps is 1'7 mm. to 2-0 mm. in length. 



Habitat. Found at a depth of two or three fathoms in Blanche Bay. New Britain. 



On first examining these colonies they appeared to belong to none of the hitherto 

 described species of Xenia. On comparing their chief characters with those of other 

 species it was found that they were most nearly allied to X. umbellata, Savigny. 

 The general appearance of the colony, the proportionate measurements and shape 

 of the parts of the polyps, the long slender pinnules — all agree with Klunzinger's 

 description of X. umhellata (1877, p. 39). There are however some differences which 

 are mentioned and considered below — 



(1) The polyps are slightly larger than those of Klunzinger's specimen, but 

 the proportion of length to width is practically identical in both. 



