420 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr, 10, 



A vertical section of the specimen showed numerous yellow ova, 

 with a diameter of 0'7 mm. 



SCLEROPHYTUM viRiDE, sp. n. (Plate XXIX. figs. 2 & 3.) 



(1) This species is represented by numerous portions of 

 very large colonies. Some of the colonies were a yard aci'oss ! 

 In the living forms the general colour was bright green, the 

 polyps were brown, the tentacles green. The stalk in one 

 specimen is 34*5 mm. in height and in the other 30 mm. The 

 portion of the crown is greatly folded and lobed, each of the 

 larger lobes dividing into smaller lobes. 



In the majority the autozooids are completely retracted within 

 the general coenenchyma, but they are very numerous, especially 

 towards the edge of the marginal lobe. The pores left by the 

 retracted autozooids are variable in size, some 0'15 mm. x 0"1 mm., 

 others 0-075 mm. x 0-075 mm., and othei^s 0-1 x 0-075 mm. Their 

 shape also varies from a circular opening to a somewhat oval- 

 shaped pore. 



Between the openings of the autozooids lie the mmierous very 

 minute openings of the siphonozooids, becoming more numerous 

 in proportion to the autozooids towards the central portion of the 

 crown. 



The spicules are of three types : — 



(a) Long slender spindles with few rough Avart-like tubercles, 



in length and breadth in millims. as follows : — 0-45 X 0-06; 

 0-3 X 0-03 ; 0-2 x 0-025. 



(b) Short, thick, double clubs with a veiy short median waist 



and with whorls of rough wartdike tubercles which carry 

 a number of small spines. They vary in length from 

 0-25-0-3 mm. and in breadth from 0' 12-0-2 mm. 



(c) Small oval-shaped spicules with many tubercles a,s in (h), 



varying in length from 0-25-0-39 mm. and in breadth 

 from 0-1-0-2 mm. 

 The last type (c) may be a modification of (b) in which the free 

 central portion has become obliterated. Among the first type («) 

 several show bifurcations at the ends. 



(2) In some other less contracted specimens the autozooids are 

 numerous, up to 7 mm. in length including the tentacles, and 

 are all marked by transverse annulations. On the tentacles the 

 pinnules are arranged in one row on either side of the middle 

 line on the oral surface ; the number in a row varies from 10-14. 

 The tentacles are short (about 1 mm.) in comparison to the 

 polyps. The stomodjeum, which is greatly wrinkled, is 1-6 mm. 

 in length. 



The siphonozooids are very numerous and small, giving the 

 surface a pitted or dotted appearance. 

 The spicules are of three types : — 



(a) Long slender spindles with very few and wart-like tubercles, 

 from 0-2-0-3 mm. in length and from 0-025-^0-03 mm. in 

 width . 



