274 



PROP. MARSHALL AND MR. G. EL FOWLER Otf THE 



leaves (fig. 8). The dorsal zooid stripe of the rachis is short, 

 consisting of 2 to 4 rows of siphonozooids placed opposite the 

 uppermost 3 pairs of leaves. 



The following table gives the principal dimensions of three 

 specimens of this variety. Of these, the first one (a) is the most 

 typical one, b and c being more divergent forms, which in some 

 respects approximate to the second variety (/3). 





a. 



b. 



c. 





108 



107 



93 





40 



51 



40 



68 



56 



53 



Width of feather 



65 



89 



51 



Width of rachis, ventral surface... 



23 



31 



18 



Distance apart of lowest leaves . . . 



11 



10 



12 





15 



15 



17 





29+4 rud. 



27+5 rud. 



27 +4 rud. 



Height of largest leaf 



14 



22 



13 





22 



28 



21 



Base of attachment of largest leaf 



7 



11 



8 





20 



18-22 



16-20 





2-2-5 



2-3 



2-2-5 



Pt. chinense, var ft. (Plate XXIII. figs. 10 & 11.) 



A single specimen of this form was obtained from the Mergui 

 Archipelago. In general appearance it agrees fairly closely with 

 var. a, from which it differs in the following points : — 



The colony is almost uniformly purple in colour ; the leaves 

 brown at the base, with a broad purple marginal band corre- 

 sponding to the zone of autozooids. The feather is markedly 

 wider than it is long. The leaves are thick and fleshy, especially 

 at their margins, and are only slightly notched between the 

 spines, and the spines are shorter. 



It is quite possible that these differences may be due to local 

 circumstances. 



The principal dimensions of this variety are as follows: — 



Length of colony 98 mm. 



Length of stalk 44 



Length of feather 54 



Width of feather 72 



Width of rachil, ventral surface 21 



Distance apart of lowest leaves 0*5 



