680 RHABDOPLEURID.E. 



Rhabdopleura ranges from about 100 to 300 fathoms, 

 and, according to Sars, is most plentiful at the greatest 

 depths*. 



RHABDOPLEURA NORMANI, Allman. 



Plate LXXXII. figs. 1, 2, and 4-7. 



RHABDOPLEURA NORMANI, Allman, in Rep. on Shetl. Dredgings, Rep. Brit. 

 Assoc. for 1867 (1868), 311 ; Quart. Journ. Micr. Sc. n. B. 

 ix. (1869) 57, pi. viii. 



Zoariwn subalternately branched, delicate, transparent 

 and colourless ; the tubular cells rising at the extremity 

 of the branches, of the same diameter as the adherent 

 portion, closed below by a thin transverse septum, 

 distinctly and regularly annulated. 



IN this species the cells are adherent at their commence- 

 ment, like the other portions of the crencecium, but soon 

 become free and erect. They are beautifully annulated, 

 whilst the adherent portions of the tube are crossed by 

 faint ridges, which pass obliquely from each side towards 

 the centre, intercepting each other in their course. The 

 axial cord is opaque and dark-coloured, and shows very 

 conspicuously through the hyaline walls of the tube. 

 According to Allman, certain bodies, clothed in a dark- 

 brown chitinous capsule, are developed on the funiculus, 

 which he regards as probably equivalent to the " state- 

 blasts " of the freshwater Polyzoa. 



HABITAT. On dead shells from deep water. 



LOCALITY. Shetland, Outer Haaf, off Unst, 93 fathoms 

 (A. M. N.). 



* See a paper, " On Rhabdopleura mirabilis (M. Sars)," by George Osaian 

 Sars, 'University Programme' for the first half-year, 1869: Christiania, 1872. 

 Reprinted in the Quart. Journ. Micr. Sc. vol. xiv. n. a. Also Allman, " On 

 Rhtibdopleura Normani," Quart. Journ. Micr. Sc. January 1869 ; and " On 

 the Relations of Rhahdopleura," Journ. Linn. Soc., Zool. vol. xiv. p. 581. 



