56 



The polyps stand in small groups of six individuals on short stalks, the 

 longest stalk measuring about 1 mm. in length. The individuals of a bundle 

 do not diverge very much. The polyps are somevrhat flat, measuring on an 

 average 072 mm. in height and 078 mm. in breadth. They are placed at an 

 obtuse angle on the stalk. The polyp-spicules are arranged in the following 

 manner : Two to three pairs of spicules may meet at an angle or be practically 

 horizontal, then above these one pair of converging spicules arises, one of which 

 is larger than the other and projects beyond the polyp. Between adjacent pairs 

 but always near the smaller of the two spicules lies another spicule of about 

 half the size. The polyp-spicules are spindles with few simple spines, and 

 measure O'SO mm. in average length, the longer of the up})ermost pair reaching 

 0'42 mm. and projecting 0'12 mm. Closely packed together on the aboral 

 surface of the tentacles are two rows of flat, toothed spicules. 



The Stiitzbiindel is well developed ; one spicule may reach a length of 3 "3 mm. 

 and may project 072 mm. beyond the polyp, but usually it is not so pronounced. 



Cortical spicules : (n) The stem contains long, slender spindles, either 

 straight or slightly curved, and sparsely covered by small spines regularly 

 arranged. They measure from 0'9 to 24 mm. in length and from 006 

 to 015 mm. in thickness. They are more or less regularly transverse in posi- 

 tion on the stem and main branches. 



(fi) Those of the stalk are slender spindles with prominent blunt warts, 

 and smaller, smoother, irregulai* spindles. They measure on an average 1 mm. 

 in length and 01 2 mm. in thickness. 



Canal-wall sj^icviles : {a) The stem has spindles, usually straight or 

 slightly curved, stringy in appearance, and practically without protuberances. 

 They average 0*42 mm. in length. There are also smooth, flat spindle- to star- 

 shaped forms. 



(b) Those of the stalk are similar to those of the stem, and in addition 

 there occur a few three-rayed forms. The spindles differ, however, in having 

 more numerous and more prominent spine-like protuberances, and average about 

 072 mm. in length. 



Colour — The colony generally is white ; exceptions are, polyp-spicules, 

 tips of the twigs, and little patches here and there on the edges of the flattened 

 branches, which are pale lilac, while a more distinct tinge of the same is seen 

 in the polyp-stalks. 



Locality : Forrest Strait, Mergui Archipelago. 



Dendronephthya crystallina, Henderson. 



The specimen is pear-shaped, regular in outline and somewhat flattened 

 in one plane. It measures 43 cm. in height and 3-9 cm. in maximum width. 



