TRANSACTIONS OF THE SECTIONS. 137 



of the globe must be iu the main solid, and of this he further avails liimself to explain 

 the phenomena of earthquakes and the so-called " magnetic stomis." 



ZOOLOGY AND BOTANY. 



The Chairman (Professor Babington), in opening tlie Meeting, made some re- 

 marts on the advantages of meetings like those of tliis Association. The great 

 object of science was the unfolding the laws by which the universe was governed, 

 and one of the greatest encouragements to this study was the assembling together 

 of men of kindred minds and similar pursuits. Sometimes ditierence of opinion 

 engendered feelings of an rmpleasant kind, which personal intercom-se served to re- 

 move ; and thus these meetings, on accoimt of their scientific and social value, had 

 become increasingly appreciated. 



On some Points in the Anatomy o/Cyprsea. By T. Alcock, M.T). 



Examinations of nmuerous specimens of Cypraa, received from the Smithsonian 

 Institiition, have led me to the conclusion that the oral organ in this genus is a 

 rostrum, capable, however, of complete retraction. The food found in the stomach 

 of the animals consists almost entirely of sponge. The teeth differ considerably 

 from one another in difterent species, but all have the essential characters of those 

 of the Rostrifera. 



The gills are two in number : one large, semicircidar, and pectinate ; the other 

 trefoil-shaped and plume-like. The whole roof of the branchial chamber behind 

 the giUs is occupied by a very large mucus-gland. 



(hi the Cosmopolitan Operations of the Smithsonian Institution. 

 By Philip P. Carpenter, B.A., Ph.D. 



An accoimt is given of this Institution at page 109 of the last volume of ' Trans- 

 actions.' At a time when political convulsions are throwing such great impedi- 

 ments in the way of Transatlantic science, it is satisfactory to know that it is only 

 in pecuniary resources that its operations have received a check. The U.S. Govern- 

 ment are simply the trustees of the fund, not its owners ; and the stores of scientific 

 material are equally available for students in all parts of the world. The policy 

 has been inaugurated of always depositing the first duplicate of tj'pe specimens on 

 the other side of the Atlantic. The accumulation of a large museum at Washing- 

 ton is not the object of the Directors, but rather the distribution of the duplicate 

 materials, wherever it can be shown that they will promote the " increase and dif- 

 fusion of knowledge among men." 



On the Variations of Tecturella grandis. 

 By Philip P. Carpenter, B.A., Ph.D. 



Of the score of so-called species of Acmaeidfe described from the Californian coast, 

 there are seven which are tolerably well established. The species of Actncea, how- 

 ever, run into each other by so many intermediate forms that their determination 

 is very difiicult. The amount of -wiiiation of which one species is susceptible is 

 well shown in Tecturella f/randis, which presents well-marked chai-acters to separate 

 it from all other species of limpets ; and yet, in about thii-ty specimens examined, 

 the ratio of the anterior portion in front of the apex to the entire length (generally 

 a constant quantity in each species) was found to vary from 1 : 7 to 1 : 20. In this, 

 as in similar cases, the facts should be tested both by the Darwinian theory and by 

 the theory of specific pennanence. It is not to be expected, in the present state of 

 our knowledge, that either theory alone will aflbrd a satisfactoiy explanation of all 

 the facts as they arise. 



