REPORT ON THE PENJSTATULIDA. 3^ 



placed very obliquely on the rachis, so that its dorsal portion, which reaches the 

 middle Hne of the rachis, runs in a longitudinal direction. The ventral margin of the 

 pinnule is concave, thickened, and beset with u-regular wart-like protuberances; whilst the 

 dorsal convex border bears the closely set poljQ^j-cells, thirty to thirty-four in nimiber, which 

 alternate in such a manner as to give the appearance of two rows. Besides the more fully- 

 developed cells, each pinnule has at the dorsal end of its polypiferous margin from three 

 to five smaller or rudimentary cells, which are not to be confounded with the zooids. The 

 polyp-cells are in part well separated, and together with the eight strong spines at theii- 

 opening, 3 to 4 mm- long; in part shorter, more or less confluent; and some are as if 

 imbedded in the pinnules, and only free at their openings. 



The rachis is nowhere free on the dorsal side of the feather, but on the ventral 

 aspect its middle line is not covered by the zooids. These are ventral and lateral. 

 The ventral zooids form thick prominent yellow spiny bands, which begin at the 

 ventral margin of the pinnule at a little distance from its attachment, run obliquely 

 upon the sides of the rachis, and end with a longitudinal streak, the point of 

 which reaches the next band of zooids, so that all the ventral zooids together form 

 one continuous line on each side, giving ofisets to each leaf. The zooids them- 

 selves are crowded on each band, larger and smaller, and largest in the neigh- 

 bourhood of the pinnule. The lateral zooids fill the intervals between the leaves, 

 are numerous toward tlie ventral side of the rachis, where they reach the ventral 

 zooids, and run out with a single row at the outside of the dorsal attachment of the 

 pinnule ; they are all much smaller tlian the ventral zooids, but they are also armed 

 with projecting spines. 



The stalk is thickened at the upper end, and seems to terminate iuferiorlv in a 

 rounded point. The colour of the whole polypidom is genei-ally red, and darker on 

 the stalk, Avith the exception of its lower end which is pale red, becoming colourless 

 towards the tip. The feather is pale red, with the exception of the poljq^-colls 

 and ventral zooids, which are yellow. The axes of the polyps and their stomach-walls are 

 also red. All coloured parts owe their colour to calcareous needles of characteristic form. 

 Uncoloured calcareous bodies are found at the lower end of the stalk. 



Maximum length of the yellow needles of the polyp cells, 

 Breadth, ....... 



Maximum length of the red spicules of the pinnules, 



Width 



Uncoloured bodies of the end of the stalk, round or elliptical, 



Length of the whole polypidom, 



Length of the stalk, 



Breadth of the feather, 



Breadth of the stalk. 



Breadth of tlie eidargement of the stalk, 



Breadth of the base of the pinnules. 



1 mm. 

 0-058 



0-85 to 0-90 

 0-021 „ 0-027 

 0-004 „ 0015 

 300 



84 



43 

 8 



10-5 



17-19 



