203 



ADDRESS OF THE TUESIDEXT, 



Prof. G. B. IIowES, Sec. L.S., etc. 

 Deliocrcd 12th Fcbruarij, 1897. 



Ladies and Gentlemen, 



Since it is your wish that I once more appear as your attorney, 

 permit me to offer a few remarks somewhat by way of development 

 of the lines which I hist year adopted, for there is no reason why 

 Presidential Addresses should not be continuous, and let us ask what 

 is the present position of our branch of science, and what the most 

 fruitful field for its immediate development. 



Our year opened full of promise for the Malacolo<?ist, for hardly 

 had it dawned when there reached us a paper by Girard ^ on the 

 remaikable 'bivalved pulmonate' (unfortunately so called) Thyro- 

 phorella Thomensin, in which he claims to have settled the systematic 

 position of that animal. Ee its ' lesser valve ' what it may, 

 a product of overgrowth of the peristome or a protective lid 

 sui generis, it is clear that it presents us with a physiological con- 

 dition for the counterpart of which we turn to the o])erculate Eugosa 

 among Corals and the unique Hhodosoma'^ among Tunicates. Once 

 again was the zoological mind turned to the part played by 

 homoplasy ; and while thus exercised there came before it the 

 full monograph of our distinguished contemporary Paul Pclseneer, 

 upon the " Air-breathing Prosobranchs and Gill-breathing Pul- 

 luonates," ^ in which, suffice it to say, our knowledge of this 

 important and fascinating subject is materially extended, and our 

 author strengthens his conclusion that Siphonaria and Gadinia are 

 pulmonates ; whilst in reviewing this paper Simroth has shown good 

 reason for suspecting* that lanthina may be an ' air-breather.' 



M. Felix Bernard, not content with the continuation of his epoch- 

 marking work upon the Pelecypodan hinge, early in the year delighted 

 us Avith a description ^ of the structure and development of a new 

 Kulamellibranch {Sdoheretia australis), which small organism he 

 obtained off the ambulacra of a viviparous Spatangoid {Iripylus 

 (■(iveniosus), with which it is commensal, from Cape Horn. Its en- 

 closed shell, its gills, and pallial chamber, are of much interest ; and 

 his promised discussion of its affinities has for us a special association, 



' A. A. Girard, Jouru. Sci. Acad. Lisbon, ser. II, torn, iv, p. 28. 



- Chevreulins of Lacaze Diithiers, Ann. Sci. Nat. (Zuol.), ser. Ill, torn, iv, p. 293. 



* P. Pelseneer, Arcli. Biol., torn, xiv, p. 351. 



* H. Simroth, Zool. Ceutralbl., Bd. iii, p. 214. 



^ F. Bernard, Bull. Mas. Ilist. uat. Paris, toiu. xxvii, p. 361. 



