76 REl'ORT — 1851. 



voyagers." If the person is suffering from sickness at the commencement of his ex- 

 periment, as soon as he grasps the glass of liquid in his hand and suffers his arm to 

 take its course, and go through the movements alluded to, he feels as if he were per- 

 forming them of his own free-will, and the nausea abates immediately, and very 

 soon ceases entirely, and does not return so long as he suffers his arm and body to 

 assume the postures into which they see7n to be drawn. Should he however resist 

 the free course of his hand, he instantlj' feels a thrill of pain of a peculiarly stunning 

 kind, shoot through his head, and experiences a sense of dizziness and returning 

 nausea. From this last circumstance, the author of the paper infers it as probable 

 that the stomach is primarily affected through the cerebral mass, rather than through 

 a disturbance of the thoracic and abdominal viscera; and he is of opinion that the 

 method of preventing sea-sickness just described (which he has found by experience 

 to be effectual), depends on the curious fact that the invoKintary motion communicated 

 to the body by the rolling and tossing of the vessel is, by the means he adopts, ap- 

 parently converted into voluntary motion. 



Drawings of New Species of Zoophytes were exhibited by Mr. Busk. 



On some Indications of the Molluscous Fauna of the Azores and St. Helena. 

 By Professor E. Forbes, F.R.S. 



Great interest attaches to the malacology of the islands of the Atlantic, on account 

 of its bearing on inquiries into the ancient conformation of land in that region, and 

 the causes of the distribution of organized beings. We have so few data respecting 

 the Invertebrata of the Azores and St. Helena, that every fragment of fresh information 

 becomes of consequence. The author has lately had opportunities of examining a 

 small collection of land shells gathered in the Azores by Mr. Macgillivray, the inde- 

 fatigable naturalist, who accompanied tlie surveying voyage of H.JVI.S. Rattlesnake, 

 and also a small parcel of littoral and sublittoral mollusks collected at St. Michael's 

 and sent to Mr. MacAndrew. From St. Helena he has recently received a quantity 

 of the shells cast on the shore, and a few recent and subfossil land shells collected by 

 Mr. Alexander, a student of King's College. 



Out of eight species of land shells from Fayal in the Azores, one is a new form of 

 Buliimis, allied to a Madeiran species ; two are Helix pauperctda and Pupa anco- 

 rostoma, botli Madeiran ; one is the Helix harbula of Charpentier, an Asturian and 

 GaUician species ; two. Helix pisana and BuUmus ventricosus, are widely distributed 

 south and west European forms ; two. Helix aspersa and H. celtaria, are cosmopolites, 

 diffused probably owing to transportation by man. 



Of the marine shells from St. Michael's, Purpura hamasioma. Haliotis tubercularis, 

 Mitrafulva, Trochus Latigieri, and Triton (variegatum), are characteristic Lusitanian 

 species, ranging also through the Mediterranean. A Liltorina is not European; it 

 is the Littorina striata of Capt. King, a species remarkable for being common to the 

 Azores, Madeira, the Cape de Verds, and the Guinea coast. A starfish, sent with 

 the shells, is the common Uraster spinosa of Europe. 



The shells brought by Mr. Alexander from St. Helena are equally interesting. To 

 the six land shells already known he adds three, a Siiccinea, a Bulivius, and a Helix, 

 the last repi'esenting, but very distinct from, the Helix guerincaria of Madeira. 



Our knowledge of the marine shells of Madeira has hitherto been entirely due to 

 Mr. Cuming, who during a brief visit to that island, dredged for a day there in 40 

 fathoms water, on a soft muddy bottom. The shells he obtained (and of which he 

 has most liberally communicated his lists) belonged to the genera Cardium, Cytherea, 

 Mitra, Clavatula, Pleurotoma, Nassa, Scalaria, Eiilima, Pyramidella, Trochus, Del- 

 phinula, Ttirritella, Nalica, Bulla, and Hyalina. The species have proved, so far as 

 they have been examined, to be, as they seemed to Mr. Cuming at the time he cap- 

 tured them, all peculiar. 



To these genera Mr. Alexander adds specimens of Lucina, Donaxi, Hipponyxl, 

 AcmcBa, Siphonaria, Fissurelta, Genu, Marginella, Cyprcea, Conus, Cassio, Colum- 

 bella, Cerithium, Fossarus and Rissoa. In the British Museum there is an unnamed 

 Littorina from St, Helena, closely represented but distinct from ih^ Littorina striata 

 above alluded to. 



