THE PLANKTON OF THE FAROE CHANNEL AND SHETLANDS. 351 



Sph^rozoum (ovodimake(?) HaccM). Plate I., Fig. 5. 



On one occasion only during two years' work have I captured in the 

 tow-net a Sphserozoum. This was at a position almost due west of 

 Papa Stour, in Shetland, and first on the 100-fathom line. 



The colony possessed a clear white and firm calymma, with thin 

 strands of finely granular protoplasm. Individuals were of compara- 

 tively large size, the largest averaging "12 mm. diameter, circular, 

 greenish yellow in colour, containing numerous small cells, and in the 

 centre one large oil drop. The individuals were surrounded by a fine 

 membrane, and there were numerous xanthellre from 12-20 round each 

 individual. It bore a striking resemblance to Collozoum except for the 

 presence in the calymma of numerous needles lying between, but not 

 upon, the individuals. They consisted invariably of a straight central 

 rod, and generally of three processes or shanks, arising at an oblique 

 angle from each end of the rod. Some rods possessed four shanks at one 

 end, but the general rule was three. They varied much in size, the 

 largest needles being : rods, '002 mm. long; shanks, "003 mm. long. The 

 latter were invariably longer than the rods. Many were quite plain, 

 but others had short, minute processes or thorns on their edges, never, 

 however, so marked as those figured in Haeckel's monograph as charac- 

 teristic of Sph. pundatum. In this species also, according to Haeckel, 

 the rod is longer than the shanks. 



The presence of scattered needles in the calymma suffices to diagnose 

 this Eadiolarian as a Sphterozoum. Pour species are described by 

 Haeckel as Atlantic or common forms : (1) Sj). hcxadiniioji (captured in 

 the Faroe Channel), having six or seven curved shanks ; (2) Sp. ovodim- 

 are (Mediterranean and Atlantic) ; (3) Sp). p)undatum (cosmopolitan in 

 warmer seas) ; (4) Sp. quadrigcminum (North Atlantic), four shanks at 

 each end of the rod. 



All colonies with tangential "punctatum" needles are placed by Brandt 

 under the designation of Sp. pundatum, but he remarks that there 

 may be many kinds. While this particular Sphserozoum is obviously 

 not the one described as Sp. liexadiiiium from the Faroe Channel by 

 Haeckel, it agrees in the fact that the shanks are longer than the 

 needles, and more or less in the size of the central capsule with his 

 Sp. ovodimare, and may be provisionally placed with that. 



COLLOSPH^PJDA. 



ChCENICOSPH.'ERA murrayana. 

 This is the commonest form of colony-building Eadiolarian occurring 

 on the coasts of Shetland, and I have found it in most tow-net captures 

 from September to March. It was originally briefiy described by 



