THE FAMILY ASTEORHIZIDiE 125 



Test with a splieriocil ur oval primordial chamber, 

 opening into a long tortuous tube, the whole often 

 adherent to the surfaces of shells or stones. Shell- 

 wall thin and finely arenaceous. Diameter of tube 

 '05 to '2 mm. There is no real evidence to establish 

 the identity of Girvanella with the above form ; it 

 is more than likely that the Girvan fossils are a form 

 of the tortuous algoid bodies common in certain 

 palaeozoic and mesozoic limestones. Jurassic to 

 Becent. (Plate 6, fig. F.) 



Genus Marsipella^ Norman. 



Test fusiform or cylindrical, wdth an aperture at 

 each end ; largely composed of sponge spicules, espe- 

 cially near the extremities. Jurassic and Recent. 



Example. — M. cylinclrica, Brady, ' Proc. Roy. Soc. 

 Edinb.' 1882, vol. xi. p. 714 ; ' Rep. " Chall." ' vol. ix. 

 1884, p. 265, pi. xxiv. figs. 20-22. 



This form has a delicate spicular test. It is widely 

 distributed, and ranges in depth from 210 to 1,900 

 fathoms. Becent. (Plate 6, fig. G.) 



Genus BJtahdammina, M. Sars. 



Test rectilinear, radiate, or irregularly branching ; 

 with or without a central chamber. The open ends 

 of the tubes forming the apertures. (?) Lower Plio- 

 coie to Becent. 



Example. — B. abi/ssoi-nm, M. Sars, ' Vidensk.- 

 Selsk. Forhandl.' 1868, p. 268; Brady, 'Rep. 

 " Chall." ' vol. ix. 1884, p. 266, pi. xxi. figs. 1-13. 



The original specimens were dredged in deep 



