32 



in its lower part. The horny nodes are short, about 1 mm. in length, while the 

 calcareous internodes are I0112:, on an averao;e 9 mm. in lenoth in the largest 

 specimen. The internodes are hollow, and are formed of concentric layers ; their 

 surface is smooth, and they are uniform in tliickness except for a slight swelling 

 just at their junction with the horny nodes. Through the centre of the horny nodes 

 a slender calcareous rod runs, forming a junction between the adjacent internodes. 



The coenenchyma is thin and transparent, allowing the nodes and internodes 

 to shine through. It contains minute spicules. The polyps are long and slender, 

 and are arranged in a sinistrorse 2/3 spiral. On each internode there are poly^js, 

 and their apices are more or less dii'ected towards one side. They have long 

 supjiorting sjjicules on the walls, somewhat stronger on the abaxial side, and 

 several always project beyond the retracted tentacles. The polyps are 3-4 '5 mm. 

 in length. 



The tentacles are short, and have one row of short blunt pinnules on each 

 side of the middle line, thus leaving a free space on the oral and aboral surf;ices. 

 The aboral free space is covered liy a band of very minute flattish spicules, which 

 are arranged with their long axes perpendicular to the length of the tentacle. 



The spicules are of the following types : 



1. Long spindles which support the polyps, 0'9-3'2 nun. in length, O'07-O'l 



mm. in breadth. 



2. Short flattish spindles, 0'075-0'3 mm. in length, 0'02-0'03 mm. in 



breadth. 



3. Short flat spicules with broad spathulate ends, 0'2-0"45 mm. in length, 



"04-0 '08 mm. in maximum breadth. 

 'This sjjecies is viviparous. Several embryos were found in one polnp. 

 They are globular bodies, O'G mm. in diameter. 

 Locality: Andamans ; 270-45 fathoms. 



Acanella rigida, Wright and Studer. Plate IX. fig. 14. 



A complete colony, busliy in sliape, 103 mm. in lieight. 



The branches arise from the horny nodes in verticels of two, three, or four. 

 The first whorl of branches is given oft' at the fourth horny node, a distance of 

 23 '5 mm. from the base. 



The axis has calcareous root-like processes. The solid calcareous internodes 

 are grooved, short near the base, varying in length from 3-G"5 mm., but long near 

 the extremities of the axis and branches, often reaching in the latter a length of 

 20-21 mm. 



The polyps are prominent, rigid, and arise singly. They are covered with fusi- 

 form spicules, and have a length of 3 "3 mm. The tentacles are not capal^le of com- 

 plete retraction. 



