326 JOURNAL OF CONCHOLOGY, VOL. 16, NO. ID, OCTOBER, 1922. 



volume is now £2Jiolo and the price of the separate parts a proportional 

 smaller sum ; that of the portion Mollusca is 5/. 



Yours faithfully, 



W. L. SCLATER, 

 ^_^ Editor Zoological Record. 



Mr. Jackson has an excellent paper in the Lancashire and Cheshire Naturalist, 

 vol. xiv, p. 147, on the Mollusca obtained from Tufaceous deposits at Caerwys, 

 Flintshire. About 43 species were obtained, eight of these being so far unknown 

 in the county in a living state. The list of species is accompanied b)i most useful 

 critical notes, and the probable history of the Tufa is lucidly worked out. 



Mrs. Longstaff published in theP.Z.S. 1921, p. 379 a series of observations on 

 the habits of certain South African Achatinas in confinement. The observations 

 covered a period of several years and were made upon Cocklitotna zebra var. 

 fulgurata Pfr. and var. obesa Pfr. Both these forms were found to be at the same 

 tjme ovoviviparous and oviparous. 



The Quarterly Journal of Microscopical Science, vol. Ixvi, pp. 159-185 contains 

 Mr. G. C. Robson's exhaustive monograph "On the Anatomy and affinities of 

 Paludestrina ventrosa Montagu." This is another of Mr. Robson's contributions 

 to our knowledge of the Paludestrinidse, a gioup which he characterises as peculiarly 

 interesting, owing to the tendency to transition from a marine to a freshwater habit. 

 P. ventrosa is stated to be a more definitely brackish-water form than P. ulvcs, but 

 seems to possess a greater adaptability and tolerance. 



Dr. A. Wagner : Die Faniilie der Clausiliiden : Rossmassler's Iconographie, 



Band xxi, Neue Folge 1913, Lieferung i. 2. 

 Idem : Zttr Anatomic und Systematik der Clausiliiden : Nachrichtsbl. deutsch. 



Malak. Gesellschaft, vol. 51, 1919, pp. 49-60, 87-104, 129-147. 

 In these treatises the author proposes a new system of classification for certain 

 groups (mainly European) of Clausilia, based not merely upon the shell, as previous 

 systems have been, but upon shell, radula, and certain soft parts of the animal. A 

 satisfactory clue to classification will never be found in any single organ; a com- 

 parison and combination of several organs will lead to better results. It is 

 remarkable how successful these classifications arrived at by the older school of 

 conchologists (Kiister, A. Schmidt, v. Vest, O. Boettger) have been, based as they 

 were on the shell alone. But it has now been established that the whole apparatus 

 for closing the shell in Clausilia (clausilium, plicae, lamellae, etc.) varies in 

 development with the altitude of the habitat, in other words, with the greater or 

 less amount of moisture in the air. Contiguity to the relatively moist air of the 

 sea-board produces similar results. The elaborate devices of Clausilia for closing 

 the mouth of the shell are not primarily a series of defences erected against the 

 attacks of invaders (beetles, flies, etc.), but a means of retaining moisture, the loss 

 of which is threatened, in this group especially, by the tenuity of the animal, 

 consequent upon the prolongation of the shell. Transition forms, connecting more 

 rudimentary with more elaborate "Schliessapparaten," may be traced between 

 mountain and valley specimens of identical species, and the same is true of the 

 Medora group in Dalmatia, and the Albinaria in the Greek islands. A further 

 moisture-retaining device is found in the characteristic blue, blue-grey, or milk- 

 white outer layer in the shells of certain groups {Alopia, Albinaria, Agathylla, etc.). 



