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



As this seems to be a variable species, we add a few notes in 

 regard to other sjDecimens : — 



(a) The colour of some when alive was blue all over ; the colour 



of the preserved specimens may show a tint of green or 

 raay be pure white. 



(b) The size of the larger zooids is variable, e. g. in length and 



bi-eadth in millims. 20 x 2-5, 15 x 2, 7 x 1'5. 



(c) No importance need be attached to cases where there seem 



to be five pinnules abreast on one side of a tentacle, since 

 these trivial deviations occur in colonies where the noi'mal 

 number of four rows is thoroughly dominant. 



(d) Another set of specimens was marked by the following 



peculiarities : — (1) Somewhat slender stalks, 17-25 mm. in 

 lieight, rise from a flat spreading membrane. (2) The 

 pinnules, which are mostly absent, seem to have been 

 decidedly shorter than the normal, a deviation which is 

 also noted by May ; but it is difficult to say how much of 

 this is purely aitificial. (3) The calcareous bodies men- 

 tioned by Kolliker, but not foinid by May, are abundant. 

 They are either spherical or roundish oval in shape and 

 highly refractive, Avith a diameter of about O'OOl mm. 

 Some yellowish spherical zoochloi'ellte, aboiit 0"36 mm. 

 in diameter, ai'e also present. 

 Locality. Zanzibar Harbour, lowest tide -level. 



Cespitularia ccerulea May. 



(1) A much-branched colony which was, when alive, of "a 

 biilliant sea-green coloui-, except the uppei- faces of the small 

 zooids which were bi'own." It seems to be refei-able to May's 

 Cespitularia coerulea, which is described, however, as " flesh- 

 coloured with a tinge of bright blue." 



This specimen agrees with May's diagnosis in having 



(1) One row of pinnules on each side of the tentacles ; 



(2) Polyp-bodies about 4 mm. in length ; 



(3) Tentacles about 2"5 mm. in length ; 



(4) No calcareous bodies. 



The mode of branching, on the whole, corresponds with May's 

 description ; but there is this noteworthy peculiarity, that one 

 division of the colony is sometimes connected with the main mass 

 by a narrow isthmus, e.g. 10 mm. in length by 1 mm. in breadth. 



(2) Another colony rises from a flattened base which spreads 

 over a part of the sui-face of a shell, the rest being covered by a 

 sponge. When alive it was described as having "pink stems 

 with slender brown zooids." The presei^ved specimen had at first 

 a greenish tinge, which was afterwards I'eplaced bj^ the usual 

 dull creamy white. 



The stalk, w^hich soon branches, is fairly firm in texture, but 

 there are no calcareous corpuscles. 



Near the base it gives off a small bi-anch which has spread over 



