15 



trace of an irregular central axis; and (2) a branched polyp-bearing portion or 

 polyparium, on which the polyps are arranged singly, or in small bundles crowded 

 together on small branchlets. The tentacles during rest are not retracted, Init 

 simply infolded, the aboral bands of tentacular spicules thus forming a pseudo- 

 operculum. The spicules are covered by rough prominent warts, and are mostly 

 straight or curved spindles. A number of polyp spicules are " golf-club " shaped, 

 i.e. are bent at a sharp angle near one end. 



Locality : Eight miles west of Interview Islands, Andamans ; 270-45 

 fathoms. 



In another haul from near the Andamans a young colony of this species is 

 included. It rises from a flat base and consists of two stems — 3 "2 cms. and 3 cms. 

 respectively in height. In this specimen the main stems do not break up into 

 branches, but give off' small twigs. They are slightly flattened, and polyps occur 

 singly over their whole surface. 



Locality: Andamans; 270-45 fathoms. 



Agaricoides alcocki,' Simpson, n. g. et sp. Plate VIII. fig. 4 ; Plate X. figs. 1-19. 



This new genus is represented by numerous specimens varying greatly in size, 

 which illustrate diff'erent stages of growth. 



The following are the measurements of some of the more perfect specimens : 



All were attached to pieces of Madrepore coral, probably Lophohelia sj). 



General Description. 



The colony consists of two very distinct parts: (1) a bare trunk, and (2) a 

 polyp-bearing " pileus." The trunk is composed of a large numljer of longitudinal 

 canals with the adjacent walls fused and densely packed with s^iicules, which give 

 consistency and rigidity to the colony. The upper umbrella-shaped portion or 

 "pileus" so closely resembles a mushroom that the term " agariciform " might well 

 be apphed. The general colour of the pileus portion of the colony is a pale orange 

 yellow, while the trunk is whitish. The zooids, whose tentacles are not retractile, 

 are introver.sible within cylindrical stalks which are expanded terminally into 

 characteristic octagonal disc-like expansions. The close-set octagons covering the 



' For a description of this remarkable new type wo are indebted to Mr. James J. Simpson, M.A., 

 li.Sc. See Zool. Aii::ei(i. xxix. (1905) pp. 2G3-271, 19 figs. 



