Manchester Memoirs, Vol. ixii. (1917). Ac 7 -5 



There are numerous small spicules on the surface oi tin- 

 stalk and rachis, others arc situated on the walls at the bases 

 of the autozooids tangential to the surface. The spicules ot 

 the external surface of the stalk which are placed nunc or less 

 at right angles to the surface, are (a) minute, oval flattened 

 discs, (b) similar forms but much longer. The smaller spicules 

 are from 0.04 x 0.02 to 0.10 x 0.04 mm., in size; the Longer 

 forms are from 0.14 x 0.04 to 0.58 x 0.06 mm.: the latter 

 spicules are more rod-like than the former and are brown in 

 stead of cream. On the outside of the polyp-bearing part or 

 rachis, the spicules are rod-like, club-like, wart like and there 

 are also crosses and other more irregular forms. These 

 spicules vary very much in size, they are sometimes from 

 0.06 x 0.02 to 0.484 x 0.06 mm. The spicules from the interior 

 of the rachis between the bases of the autozooids are as a rule 

 much larger than the preceding, frequently about 0.50 > 

 0.10 mm. in dimensions. The size of the spicules does not 

 appear to be a point of much specific importance as it is so 

 varied. A marked characteristic of many of the spicules is the 

 occurrence of well denned lines of growth. A point which 

 I wish to find out later, when I have more specimens is how 

 these lines of growth vary in specimens of different size and 

 age. 



This species was first described by K ("-Hiker from the Bay 

 of Bengal. Thomson and Simpson have also recorded it from 

 the Indian Ocean, namely from the Orissa Coast, from Sand- 

 heads, R. Hughli and from Calicut. 



Hickson's definition of the genus Cavernularia is "Colonies 

 usually club-shaped with small and usually completely retrac- 

 tile autozooids. Spicules of rachis rod-shaped and occasion- 

 ally branched at their extremities. No spicules in the tentacles 

 of the autozooids and rarely (C. pusilla) in the body walls of 

 the anthocodiae. Axis frequently absent, sometimes abbrevi- 

 ated, rarely complete." There is, however, an oversight in 

 Hickson's table of the species of Cavernularia in which he 

 states that C. liitkenii has a complete axis. Kolliker's diag- 

 nosis of Cavernularia Liitkenii was as follows: — Stock klein, 

 keulenformig. Kolben 2), mat so lang als der Stiel. und fast 

 doppelt so breit. Polvpen klein. entferntstehend. braun, ohne 

 Kalknadeln. Zooide zahlreich, farblos. Stiel mit dicker, in 

 Kalkkorpern sehr reicher Cutis und wenig entwickelten, in 

 Kalkkorpern sehr armen Muskellagen. Axe drehrund, im 

 oberen Theile des Stieles und in der unteren Halfte des Kolbens 

 gelegen. Kolben mit vielen Kalknadeln bis in die Septa der 

 Hauptkanale hinein. Kalkkorper mehr weniger abgeplattet. 

 im Stiele langlichrund, spindel — oder keulenformig, 0.03 — 



