116 Rev. T. Hincks's Contributions towards a 



Fig. 9. An A. actinophora with a distinct cortical layer (rs), and a tuft 

 of pseudopodia at one end (Hartuack, oc. 3, obj. 7). 



Fig. 10. Another with few pseudopodia, distinctly showing- how they 

 break through the cortex. (Rather too large in proportion to 

 the following figures.) 



Fig. 11. The same example a short time afterwards. The cortex (?• s) is 

 almost everywhere liquehed, and has become converted into a 

 clear space ( h) : n, the nucleus, which is distinctly visible in 

 this state. 



Fig. 12. The same, with the cortex completely dissolved, v c, contractile 

 vacuoles. 



Fig. 13. The same, in slow flow in the direction indicated by the arrow, 

 r s, the newly reconstituted cortex. 



Fig. 14. Another example, in which the cortex has just become liquefied, 

 but is still retained at one spot, together with two pseudopodia. 



Fig. 15. An Atnaba in which the cortex has dissolved before two pseudo- 

 podia (;;s) were retracted. These become liquefied soon after- 

 wards. In this and 



Fig. IG the granular protoplasm is sharply separated from the hyaline 

 zone. This, however, only lasts for a few moments, to give 

 place to the state in fig. 12. 



Fig. 17. An Ainoeha in which the liquefaction of the cortex had just 

 commenced on one side, treated with osmic acid. The cortex 

 (r s) appears finely punctate, as also the hyaline sarcode ; the 

 nucleus at n. 



XV. — Contributions towards a General History of the Marine 

 Polyzoa. By the Rev. Thomas Hincks, ]3.A., F.R.S. 



[Continued from vol. viii. p. 136.] 



[Plate v.] 



IX. FOREIGN CHEILOSTOMATA (Miscellaneous). 



Family Flustridae. 



Flustra, Linna3us. 

 Flustra dentigera, n. sp. (PI. V. figs. 7, 7 a.) 



Zoarium of a ratlier dark-brown colour and a somewliat 

 waxy appearance, with a narrow smooth edging, dividing 

 dichotomously into tall, linear, strap-like segments, expand- 

 ing very slightly upwards, which are not divergent, but con- 

 tinue in close proximity throughout their length. Zooecia 

 alternate, elongate, arched above and somewhat expanded, 

 usually narrowing slightly below the middle, a line of uume- 



