182 CEYLON PEARL OYSTER REPORT. 



closer, often S-shaped, translucent, with distinctly separated calices, and in other 

 characters. 



Family : CAVERNULARIID^E. 



Fusticularia herdmani, Simpson Plate, figs. 16 to 22, and text-fig. 2. 



I entrusted to Mr. J. J. Simpson, M.A., my private assistant, a small club-like 

 specimen which had been overlooked in the first study of Professor Herdman's 

 collection. It had, indeed, so much resemblance to a corticate sponge that it was 



originally sent for examination to Professor Dendy. The 

 accompanying text-figure (fig. 2) is a reproduction of a 

 drawing of the colony made by Professor Dendy. 



Mr. Simpson has published an account of this interesting 

 form in the ' Annals and Magazine of Natural History,' xv. 

 (1905), pp. 561-5, 1 plate, and has named it appropriately 

 Fusticularia herdmani, gen. et sp. n. 



The specimen is a small free-living sponge-like colony, 

 37 centime, in length, 1*7 centims. in breadth, and 1 centim. 

 thick. It consists of a flattened ovoid stock separated by a 

 constriction from a comparatively slender trunk 1 "2 centims. 

 long and 0"6 centim. in breadth. 



The general colour is a dark brown, approaching 

 chocolate. 



The zooids are dimorphic, the smaller siphonozooids being 

 scattered irregularly among the larger autozooids, which 

 Pig. 2. Fusticuiaria herdmani, ai 'e separated by distances varying from 1 millim. to 

 .Simpson, x 2. 3 millims. The zooids are completely retractile into pit- 



like depressions, about 0*5 millim. in diameter. The length 

 of a fully expanded autozooid is about 0'75 millim. to 1 millim. and the tentacles 

 measure 07 millim. 



Three longitudinal canals traverse the colony throughout its entire length. 

 The coenenchyma is densely spiculose. The spicules, which vary greatly in form 

 and size in the different parts of the colony, are arranged in bundles supporting the 

 polyp cavities. All are hyaline and smooth and the majority bear blunt digitiform 

 terminations which are often marked by characteristic annulations. The most 

 frequent types are the following : blunt spindles, cylinders, clubs, double barrels and 

 palmate forms. They vary in size from - 3x0 - 05 millim. in the cortical layer of the 

 stock to - 45x0 - 025 millim. in the trunk. Among the characteristic features of this 

 genus the following are most noteworthy : (a) the minuteness of the zooids ; (b) the 

 absence of an axis ; (c) the broadly palmate spicules ; (d) the elliptical trunk ; (e) the 

 constriction between stock and trunk; (f) the number (3) of canals in the stock ; 

 (g) the small number of autozooids. 



