Mr. A. Adams on a supposed new Genus of Pelagic Mollusca. 401 



found to be identical. The quantity existing in the Yerba de 

 Paraguay has not been ascertained, but it is probably not less 

 in amount than in coffee. Coffee, however, derives its pleasant 

 flavour principally from its peculiar acid, called caffeic acid, 

 which is very analogous to kinic acid, or the vegetable acid of 

 Cinchona-barks. Dr. Stenhouse relates that when caffeic acid 

 is treated with sulphuric acid and binoxide of manganese, it 

 yields the peculiar principle called kinone, and that the Paraguay 

 tea also furnishes kinone when subjected to a similar treatment. 

 It is worthy of notice that the leaves of our common Holly, 

 when exposed to the action of the same reagents, also yield 

 kinone, as do the whole of the Cinchona tribe of plants and 

 Asiatic Tea. There is another vegetable product of an analogous 

 nature, the guar and, or inspissated juice of the Paullinia sorbilis, 

 prepared by the Indians of Para, the infusion of which affords a 

 very refreshing drink, of which the Indians are very fond. This 

 has been analysed by Dr. Stenhouse, and found to contain a 

 large proportion of theine. It is singular that Man, in the 

 lowest grades of civilization, should have had the faculty of 

 distinguishing and applying to his use those plants which con- 

 tain the peculiar principle to which the tea of China owes its 

 invigorating property. 



XL. — On a supposed new Genus and on some new Species of 

 Pelagic Mollusca. By Arthur Adams, F.L.S. &c. 



As the little floating forms of Mollusca which inhabit the high 

 seas are so little known and so seldom met with, I consider it 

 interesting to the zoologist that the capture of every novel ex- 

 ample should be recorded, even supposing the presumed " new 

 genus " should hereafter be proved to be merely a synonym of 

 some well-known type. Thus Zoea of Leach led the way to 

 Thompson's revelations of the metamorphoses of the Crustacea, 

 and Cirrhopteron of Sars to those of the Mollusca. Sinusigera 

 of D'Orbigny has been said to be the larva of Dolium, the nu- 

 cleus of which, however, is smooth and tumid, and the outer lip 

 thin and simple. The same species, S. cancellata, has also been 

 supposed by Macdonald to be the young of a very different 

 shell, namely Pedicularia. The nearest approach to the small 

 shells described below is Sinusigera ; but if they be the fry or 

 embryonic condition of some other mollusk, I cannot imagine 

 to what known genus they can be affiliated. 



Genus Alciope, A. Adams. 

 Testa dextrorsa, spiralis, trochiformis ; anfractuultimo ad peripheriam 

 Ann. $ Mag. N. Hist. Ser.3. Vol viii. 26 



