ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



185 



first theca passes gradually into the common canal of the primordial 

 stipe as well as into the apertural part of the theca. In Isograptus, the 

 cavity of the ramifying portion of the first theca passes gradually into 

 its apertural part, but into the common canal of the primordial stipe 

 by means of a very constricted foramen placed near the prolific side of 

 the sicula. In Mceandrograptus, the cavity of the ramifying portion 

 ■of the first theca is in direct communication with two or three thecae 

 of the primordial stipe. Of the two last-named genera, established by 

 Moberg (1892), only one species is known. They are very distinct 

 from Didymograptus, but perhaps they should be ranked as sub-genera. 

 Tornquist describes eight new species of Didymograptus. 



Protozoa. 



Cymbalopora bulloides.* — A. Earland has paid particular attention 

 to the final inflated portion of the shell of this Foraminifer, the so- 

 called " balloon " chamber, and finds that it incloses another very 

 delicate chamber, the " float " chamber. This inner chamber has a very 

 delicate imperforate calcite wall, it is not attached to the inner surface 

 of the balloon chamber. It is attached to the lower surface of the 

 upper or spiral shell, but has no direct connection with these upper 

 chambers, the only opening into its interior consisting of the small 

 tube in the centre of its base, as discovered by Mobius. 



New Coccidian.f — M. Siedlecki has found in the mature males of 

 the Polychset Polymnia nebulosa a large Coccidian which he calls Caryo- 

 tropha mesnilii g. et sp. n. Like other Coccidia, it is an intracellular 

 parasite, and occurs in the packets of spermatogonia, never more than 

 one in each. The " indifferent adult " form may multiply by division 

 into merozoites (mononts, schizonts), or it may reproduce sexually. In 

 the first case the Coccidian does not leave its hypertrophied cell-host, 

 it gives rise to m " Monontocytes " which produce m n Mononts, 

 whence adults develop. The sexual reproduction may be summed up 

 as follows : — 



Cocc. adult 

 indifferent 

 Cocc. adult 

 indifferent 



12 y eporozoites «- 



-> reduced macrogamete 

 -» n microgametocytes - 



y sporocyst8 ■ 



"J conjugation 

 of macro- 



. ( and micro- 

 n x microgametes J gamete 



oocyst 



* Journ. Quekett Micr. Club, viii. (1902) pp. 309-22 (1 pi. and 3 figa.). 

 t Bull Internat. Acad. Sci. Cracovie, No. 8 (1902) pp. 561-8 (5 figs.). 



• i < ^»-«- 



