68 



transverse spicules ; between the double rows, directly below the transverse 

 spicules, lie two curved spicules, concave side upwards ; above the ring of 

 transverse spicules rise eight points each consisting of at least one pair of con- 

 verging spicules, of which one is much larger and projects considerably ; in 

 addition there is a single curved spicule lying between adjacent upjjerniost 

 pairs and so placed that it appears to strengthen the basal attachment some- 

 times of the larger and sometimes of the smaller. The converging i)air run 

 practically parallel for a considerable distance, and in the divergence at their 

 base there is sometimes an extra spicule which lies close to and runs parallel 

 to the basal portion of the larger spicule. The spicules are flattened curved 

 spindles from 016 to 030 mm. long and averaging 0017 mm. in breadth. The 

 projecting spicule may measure up to 1 mm. in length and may project for a 

 distance of 0"48 mm. beyond the polyp-head. On the aboral surface of each 

 tentacle there are two rows of smooth flat rods, the inner ends of which alter- 

 nate more or less regularly with one another, being thickly crowded together. 

 They have an average length of 01)21 mm. 



The Stutzbundel is modei'ately developed and consists of a number of 

 spicules which measure about 2 mm. in length. One projects for a short dis- 

 tance beyond the polyp. 



Cortical spicules : (a) In the stem there are slender spiny spindles straight 

 or curved, varying from 0'04 to 2'9 mm. in length. 



(b) In the stalk there are slender spindles straight or curved, thickly 

 covered by spines, irregular three- and four-rayed forms and a number of 

 irregular forms with prominent irregular or branched spines ; there are also 

 smoother, flattened forms with a few blunt spines. Spindles vary from O'2-l to 

 2'4 mm. in length and from 0'032 to 0'176 mm. in breadth. The rayed forms 

 may reach a length of 04 mm. The irregular forms are irregular clubs or 

 spindles with a large number of prominent spines aggregated at one end. The 

 small, smooth forms vary in length from 0"064 to 0'16 mm. 



Canal-wall spicules : (a) Those of the stem are similar to those of the 

 stem coi'tex, and in addition there is a number of irregular forms with rough 

 spines. Spindles may reach a length of 00 mm. and a breadth of 0112 mm. 



(/>) Those of the stalk are smooth, flattened, three- and four-rayed forms, 

 numerous irregular branched forms, and a number of spindles straight, curved, or 

 irregularly sigmoid, with pointed or blunt ends. On the surface of each spicule 

 there are scattered a few inconspicuous smooth rounded warts or blunt spines. 

 Spindles may reach a length of 0*64 mm. and a breadth of 008 nun. The rayed 

 forms have a maximum length of 0560 mm. 



Colour — The larger spicules of the stalk are opaque white in the central 

 portion, otherwise the stalk appears greyish- white ; stem and branches greyish - 

 white ; polyp-stalks and heads light cinnamon-brown. 



Locality : Andamans. 



