Miscellaneous. 431 



Bottom fauna : Protozoa : — Bifftugia pyriformis, Perty. 



Gentropyxis aculeata, Ehr. 



Note. — AnurcBct lonyispina is present in all basins. 



Particularly noticeable are : — Dinohryon sertularia, var, alpinum, 

 Imh., previously met with only in a small geographical region on 

 the Bernina, and the occurrence of Drepanothrix dentata, Euren, 

 characterized by the tooth about the middle of the dorsal ridge, 

 which was quite recently discovered in France near Tulle. — Zoolo- 

 gischer Anzeiger, No. 290, October 8, 1888, p. 5G5. 



On ^gyria oliva, Clcq). <^ Lachm. By Dr. L. Plate. 



In his memoir ' Ueber Infusorien des Golfes von N eapel,' Geza 

 Entz remarks of ^gyria oliva : — " The nucleus is situated beneath 

 the oesophagus. It is a large, clear, round or oval body with a 

 transverse fissure ; on various parts of its surface I was able to dis- 

 tinguish a nucleolus quite clearly, even without the employment of 

 reagents." To this short description I would add something, as the 

 nucleus of this Infusorian presents a somewhat unusual struc- 

 ture. It is, in fact, composed of two halves which behave differently 

 with staining materials, in the same way as is known to be the case 

 in Spirochona gemmipara, Leptodiscus medusoides, and some Bhizo- 

 poda. After the animal has been killed with osmic acid one half of 

 the nucleus presents a darkly granular appearance, while the other 

 looks nearly homogeneous and clear, only having a very slight 

 granulation at its foremost pole. The two divisions lie close 

 together, but are separated by a distinct line, so that the transverse 

 fissure observed by Geza Entz must have been an artificial one. On 

 the application of solution of carmine the clear half of the nucleus 

 becomes intensely and the dark one very faintly coloured. The 

 nucleus of JEgyria oliva therefore behaves with staining materials 

 just in the opposite way to that of Spiroclwna gemmipara, in which 

 the darkly granular part is the chromatic and the clear part the 

 achromatic part. It would be interesting to ascertain whether in 

 the one form the nuclear division is of so complicated a nature as in 

 the other ; for if this were the case we should be justified in regard- 

 ing the separate arrangement of the chromatic and achromatic 

 nuclear eleiiients as the cause of such a mitosis. — Zoologische Jahr- 

 biicJier, Abtheil. fur Aiiat. und Ontogenie, Band iii. p. 173. 



On Heliochona sessilis, a new VorticelUne. By Dr. L. Plate. 



On the branchial plates of a Gammarus from the North Sea I 

 have found a new Vorticelline, the nearest allies of which are to be 



