70 BICELLAEIID^. 



the friendly shelter. There is usually one dorsal spine 

 placed on the inner side, a little behind the margin ; and 

 sometimes a second is present. Just at the point where 

 the narrow, cylindrical portion of the cell commences, 

 there is a kind of joint. The ovicell does not rise fi'om 

 the margin, but from the side of the cell a little below it, 

 and is distinctly pedunculate. Its opening is turned to- 

 wards the aperture, which it overhangs*. 



The avicularium presents no very marked feature, if we 

 except the serrate beak. It is rounded behind, but not 

 arched above, the upper surface being remarkably straight ; 

 the beak is short, and scarcely hooked at the point. 



The shoots rise from a bundle of fibres which are carried 

 up for a short distance upon the surface, involving the 

 cells near the base. 



No description or drawing, I may add, can give an 

 adequate idea of the beauty of this species, or do more 

 than suggest the charm which lies in its exquisitely soft 

 feathery tufts, its transparent whiteness, and its graceful 

 habit. 



BiCELLARIA AlUERI, Busk. 



Plate IX. figs. 3-7. 



BiCELLAUiA Alderi, BusJc, Eep. B. Assoc. 1859, Trans. Sect. 145; Quart. 



Journ. Micr. Sc. ISfiO, 143, pi. xxviii. figs. 1-3: Smift, 



CEfvers. K. Vet. Akacl. Forhandl. 18G7, 289 and 335, pi. xviii. 



figs. 4-8 : Norman, Quart. Journ. Micr. Sc. viii. 218. 

 BiCELLAuiA rNispiNosA, Savs, N. Mag. f. Naturv. B. xii. 286; Geol. ogZool. 



lagttagelser &c. (1863) 34. 



Zoarium white and transparent, dichotomously branched. 

 Zocecia in two series, alternate, very loosely connected 



* The structure of the ooecium has been admirably demonstrated by 

 Nitsche in a paper "On the Developmental History of certain Cheilosto- 

 niatous Bryozoa," Zoitschr. f. wissenschaft . Zool. Band xs. Heft 1 , pp. 3, 4. 



