348 THE PLANKTON OF THE FARoE CHANNEL AND SHETLANDS. 



upon living specimens has been possible, since I have captured it in 

 the several stages of development, including the spore-formation stage. 

 The colonies are for the most part globular, never segmented like 

 Coll. inerme, the calymma is delicate and packed with zooids of •12--15 

 mm. diameter (smallest) to "24 mm. (the largest), many in the same 

 colony being quite round, others ovoid or elliptical, but varying as 

 much in shape as size, long, fiddle-shaped (dividing) zooids measuring as 

 much as "34 mm. in length. 



Similar variation existed in the number and size of the oil drops, the 

 occurrence of one oil globule being quite exceptional, most colonies, 

 except those in the spore stage, containing zooids with a central rosette 

 of eight or nine colourless oil drops, while in long, tiddle-shaped zooids 

 they were more numerous still. The xauthellae were very numerous — 

 in many of the young reproductive colonies from 20-30, in individuals 

 of other colonies, which are apparently the same species, being as many 

 as 80-100 per individual. Staining with osmic acid failed to reveal any 

 "assimilation plasma" (Brandt), and the pseudopodia were very fine and 

 the pseudopodium bed surrounding the capsules of moderate thickness. 

 While a detailed description is reserved for a further occasion, it is 

 evident that the organism is not Coll. inerme or Coll. i^elagicum, and I 

 have little doubt that it is a new species. What is a further pecu- 

 liarity is that the calymma is filled with diatoms exactly similar to 

 those described by Brandt (and figured in Plate 2, Fig. 9, of his 

 monograph),* f long bodies (-085 mm.) tapering to a fine point at each 

 extremity, thicker in the middle, containing yellow pigment granules 

 and four or five lightly refracting dots which stain darkly with osmic 

 acid. They possess a certain degree of movement in a longitudinal 

 direction, and I have watched them making to-and-fro movements of 

 considerable length through the jelly. Some colonies have a yellowish 

 appearance, to the naked eye, and this appears to depend mostly, if not 

 entirely, upon the number of diatoms present, for the number of 

 green cells does not appear to make any difference, and the oil drops arc 

 in all cases quite colourless. 



Brandt has already described the occurrence of these diatoms in 

 four colonies of a young kind of Collozoum, which he found in the 

 Mediterranean and which did "not appear to be identical with any 

 known species." The zooids in his Collozoum had a diameter of only 

 •07-'09 mm. and contained one colourless oil drop of •023-'03 mm. 

 diameter with a small pseudopodia layer and no assimilation plasma. 

 This is practically all the description which he was enabled to give of 

 this Collozoum, for which he was unable to assign a specific place. 



* Die Kolouiebildeuden Radiolarien, 



t This does uot appear to be au accidental oceuireuce, but a constant iissociation. 



