15 



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

 polyparium, on \vliich the polyps arc arranged singly, or in small bundles crowded 

 together on small branchlets. The tentacles during rest arc not. retracted, but 

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

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

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

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



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

 fathoms. 



In another haul from near the Andamans a young colony of this ,-peci. 

 included. It rises from a flat base and consists of two stems 3'2 cms. and :! cma 

 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, 1 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 si/c, 

 which illustrate different stages of growth. 



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



Total height. Maximum breadth. Length of Trunk. Thickness of Trunk. 

 3 cms. 3 cms. 175 cms. 1'5 cm.-. 



2*5 ,, 3 ,, 1'5 ,, 1 ,, 



3-2 1-5 2-2 0-8 



0-9 1-2 0-8 0-6 



All were attached to pieces of Madrepore coral, probably Lj>l>ol><'lin sp. 



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 number of longitudinal 

 canals with the adjacent walls fused aud densely packed with spicules, which give 

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

 " pileus" so closely resembles a mushroom that the term "agaricif'orm " might well 

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

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

 are iutroversible within cylindrical stalks which are expanded terminally into 

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



1 For a description of this remarkable new type \ve are indebted to Mr. James .1. Simpson, M.A.. 

 ll.Sr. See Zool. An::eiy. xxix. (1905) pp. 263-271, 19 figs. 



