ZOOLOGY AND BOTANY, MICKOSCOPY, El'C. 39 



gigas (D'Orbigny) Pfeffer, over four feet long inclndiiig the tentacles, 

 and with peculiar features in its suckers. This prize was got from 

 Monterey Bay. 



y- Gastropoda. 



Structure and Affinities of Gadinia.* — W. Schumann gives an 

 account of the structure of this limpet-like. amphibious Gastropod. He 

 de:ils with G. peruviana Sowerby and G. garnoli Payraudeau. He shows 

 that Gadinia is really a Pulmonate, and he discusses the affinities with 

 Auriculidffi, but in particular with Siphonaria. It is probable that these 

 two interesting types, Gadinia and Siphonaria, have diverged from a 

 common stock. 



Structure of Chilina.f — AVerner Haeckel gives a detailed account 

 of Ghilina, ])ased on the study of several species. As regards nervous 

 system, reproductive organs, relation of heart and kidney, the diverti- 

 culum of the mantle cavity, the dorsal and ventral ciliated ridge in the 

 mantle cavity, and so on, there is a close resemblance between Ghilina 

 and Latia, and the latter may be included with the former in the family 

 Chilinidae. It seems likely that both types arose from an Antarctic 

 ancestor resembling Actaeon. 



Snail's Indifference to Lig-ht.^ — Emile Yung points out that field 

 observations on Helix pomatia suggest that it is lucif ugous, while Willem's 

 experiments indicate that it is positively phototropic. Over 2000 obser- 

 vations of 176 individuals lead Yung to the conclusion that the snail is 

 quite indifferent. Their distribution in light and shade is fortuitous, 

 except that the shaded areas are sometimes damper. The tentacles do 

 not react to light-stimulus of any kind ; obstacles are not seen ; amputa- 

 tion of the eyes makes no difi'erence. The vineyard snail is not derma- 

 toptic in any degree and its eyes have no visual function. 



Snail's Horns.§ — Emile Y'ung gives a detailed account of the 

 minute structure of the larger tentacles of Helix pomatia, discussing in 

 particular the blood supply, the tentacular nerve, its optic branch, and 

 the eye itself. He also describes some interesting abnormalities. 



5. Liamellibranchiata. 



Brood-pouches of Cyclas cornea. |l—HeIene Schereschewsky finds 

 that the brood-pouches are formed by a diverticulum of the lamelke of 

 the internal gill, and project freely into the cavity of the latter. 



The internal lining of the brood-pouch and the partition-walls con- 

 sist in part of a glandular nutritive epithelium. The elements of this 

 epithelium are formed in the thickenings or " crypts " which arise at the 

 transition between the gill lamellaj and the brood-pouches and partition- 

 walls. 



In the formation of the secretion there is emigration of nucleoli and 



* Zool. Jahrb., Supp., Fauna Chilensis, iv. (1911) pp. 1-88 (6 pis. and 7 figs.). 



t Zool. Jahrb., Supp., Fauna Chilensis. iv. (1911) pp. 89-136 (5 pis.). 



X Comptes Rendus, civ. (1911) pp. 434-6. 



§ Rev. Suisse Zool., xix. (1911) pp. 339-82 (4 pis.). 



ll Zeitschr. wiss. Zool.,xcviii. (1911) pp. 677-95 (1 pi. and 1 fig.). 



