ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 239 



rMzopod rolled over the field, the spines were loosened and fell off, yet 

 that rotifer remained in the corner where she first appeared, pressed 

 down by the Acanthocystis' body-mass, although her efforts were con- 

 tinually nothing less than frantic. For six hours the struggle lasted ; 

 from 14 to 20 o'clock the microscopic creatures were under uninter- 

 rupted observation. Finally, after a short rest on the rotifer's part, 

 there occurred one of the most amusing exhibitions of intelligence in 

 these lowly organisms that I have ever seen. It was indeed a most 

 masterly piece of strategy. The rotifer began to eat ! Protoplasmic 

 jelly, chlorophyll-corpuscles, half-digested food-particles, everything 

 the Acanthocystis contained streamed down into the rotifer's trans- 

 parent stomach. With short intervals, which she improved by butting 

 against the wall, she ate until she arrived at the central nucleus, 

 when, apparently perceiving that her object was accomplished, she 

 stopped, and then — it really did seem as if she was celebrating her 

 victory — then she laid an egg ! 



The rhizopod once dead and half empty, the brave rotifer selected 

 the spot at which she intended to leave, and left. It is a curious fact 

 that, having chosen the place for exit, she continued to beat against 

 that point only, until the basal plates were forced aside, and she was 

 free. Circling once or twice around the dead Acanthocystis she darted 

 from the field, followed by applause, and a few remarks of approval 

 from the spectator. 



By 24 o'clock the ovum that had been extruded in my presence as 

 well as in prison, which I had seen rolling down the half-empty 

 Acanthocystis' sac, had accomplished a part of its internal changes, but 

 an awkward movement displaced the cover-glass, and ruined all. 



Did that unhappy rhizopod in an absent-minded moment take in 

 an egg, and did that egg eventually take in the rhizopod ? Was the 

 development of the egg so far advanced that the rotifer was hatched 

 before it could be digested ?" 



Ccelenterata. 



New Alcyonarians, Gorgonids, and Pennatulids of the Nor- 

 wegian Seas.* — J. Keren and D. C. Danielssen have published 

 another of their beautifully illustrated works on the fauna of the 

 Northern Seas ; they describe a new genus Duva, in which they place 

 three new species, and the Oorgonia fiorida of J. Eathke, which is not 

 the same form as the Gersemia florida of Marenzeller. The other 

 new genus is Gondul, for which it is necessary to establish a new 

 family of Pennatulids — Gondulece — characterized as having the rachis 

 fixed, with developed bilateral pinnules, and furnished with long 

 calcareous spicules. The stalk in Gondul has a canal in its centre, 

 which is divided by four valves into as many longitudinal canals. 

 The genus Cladiscus is removed from the family Protocaulidse, where 

 it was placed by KoUiker, to the Protoptolidee, in consequence of the 

 presence of well-developed "cells." A number of new species are 



* 4to, Bergen, 1883, xvi. and 38 pp. (13 pis.). 



