"296 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Pennsylvania Fishes.* — Henry AV. Fowler gives records of the 

 fishes kuown to occur in the State of Pennsylvania. The special feature 

 of the records is that they note the distribution of the species in the 

 various lakes, streams, etc., throughout the State, and for some localities 

 the notes are regarded as practically complete. 



Lacustrine Deep-water Fauna. f — F. Zschokke discusses the fauna 

 of the depths of the Yierwaldstiittersee. From depths of 170-21-4 

 metres he obtained 100 species, including (a) littoral forms, which have 

 migrated downwards, and (b) genuine abyssal forms which represent 

 relicts of a stenothermal post-glacial fauna. 



Marine Zoological Laboratories. :j: — P. Francotte gives an interest- 

 ing illustrated account of the marine zoological laboratories at Naples, 

 Roscoff, Banyals, Concarneau, and Yillefranche. He traces their history, 

 and points out the special facilities which they severally afford. He 

 states that it was P. J. van Benedcn who established the first laboratory 

 of marine zoology (1842). 



Effect of the Eruption of Vesuvius on Marine Fauna.§ — Salvatore 

 Lo Bianco gives an interesting account of the effects of the showers of 

 ashes from the 1906 eruption of Vesuvius on the marine fauna of the 

 Gulf of Naples. Many animals were killed, the plankton was much 

 affected, the distribution of certain forms was altered, autotomy was 

 observed in hydroids, Antedon and Tunicates ; in some cases, e.g.FoIynmia 

 nebulosa and Aricia fmtida. the liberation of ova was retarded. 



INVERTEBRATA. 

 Mollusca. 

 7- Grastropoda. 



Phylliroe'll — N. VessichelU has made a study of PhylUro'e bucephala 

 Peron and Lesueur, with especial reference to the nervous system, the 

 rudiment of the foot, the cutaneous glands, and the digestive organs. 

 The family Phylliroidje includes Phylliroe bucephala, Ph. atlantica, 

 Ctilopsis picteti, Acura lanceolata, and A. pelagica. 



Composition and Development of the Radula.lF — Igerna B. J. SoUas 

 has studied this in Patella, Cryptobranchia, Acnuea, Lepeta, Trochus, 

 Littorina, Baccinum, Helix, and other forms. She finds that in all the 

 odontophorous mollusca the radula has an organic basis of chitin. The 

 Docoglossa are unique in the composition of their teeth, of which the 

 most important constituent is silica hydrate or opal. All the other 

 groups, including the Rhipidoglossa, form a second type in which the 

 radular chitin is hardened superficially by deposits containing calcium, 



* Amer. Naturalist, xli. (1907) pp. 5-21 (1 fig.). 



t Arch. Hydrobiol. Planctoukunde, ii. (1906) heft 1, pp. 1-8. See also Zool. 

 Zentralbl., xiii. (1906) pp. 551-2. 



X Auu. Soc. Beige Microscopie, xsviii. (1907) pp. 1-44 (15 figs.). 



§ j\IT. Zool. Stat. Neapel. xviii. (1906) pp. 73-104. 



II Tom. cit., pp. 105-35 (2 pis.). 



t Quart. Journ. Micr. Sci., li. (1907) pp. 115-36 (1 pi.). 



