the divergenteided whorl is noticeable. 1 This is often replaced by a p irallel-sided 

 whorl un the fourth volution, and tins in its turn ia replaced by the convergent 

 of the fifth whorl. 1 The divergent-sided whorl, with ita tuberculated pilte, 

 i» skipped in the development of some specimens of i Mutton, and it is replaced on 

 tin- third whorl by tin- parallel-sided smooth whorl and pitas of the later Btage, 

 instead of on tin- fourth whorl, as described abov< 



Tin' broad abdomen and tin- correlative divergent-sided larval form <'! 



ned in the adults of some varieties, 4 bu( even in these the pilae 

 nnooth ami without genicular, and tin- whorls diacoidal. Notwithstand- 

 ing tlii- fact ami the enormous si/«' reached by some normal specimens before 

 manifesting old age, there an- specimens in tin- closely allied .1-/. slcllon ami 

 which exhibit a remarkable tendency to assume retrogressive char- 

 and to inherit them in their youngei while still becoming 



more involute ami holding the keel comparatively unchanged. These characters 

 induced me at first t" estimate the whole Beriea ilogous, but this 



eannol he maintained. Most specimens lose the tubercles early, or <1<> not have 

 them at all. the pike become nun- folds, ami bend forward, the keel being low 

 nml broad ami the channels shallow. There is so close a resemblance between 

 these ephebolic characteristics and the oM i - of the common English 



form ol / ' Lyme I.' cially in the stout varieties of I'l'liisum, 



that collectors frequently call the old of Bucklatidi by the name ol Amm. ■ 

 Upon one occasion 1 was myself completely deceived by the exposed portion of 

 a whorl, which, when finally cleared of its surrounding matrix, was readily iden- 

 tified as a Benile specimen of typical Bucldandi. Nevertheless the characteristics 

 when compared with the radical Aga i m, are not 



is, but nealogic. They have the same relation to the characterist 

 radical forms that the fold-like pilffl ami immature whorls ol' CaL> 



of its immediate radical, P Their real value as 



shown also by the fact, that in some lull grown specimens of 



ind in the ephebolii the next 



I arietian characters appear, namely, deep channels, well 



I. and quadragonal form. The-- therefore occur in tin' -aim- - 



- in other Beriea of the A nd during the growth of the individual 



they appear in similar order. 



I econd and last of this Bubseri rarely, hut i^ 



found in several collect It has young until a late period precisely identical 

 with the young of certain varieti fobttuum, and the adults of tUUart. 



which may last until the individual- are from 76 to s'.l mm. in diameter. 



is immediately followed bj a which tin- involution i~ increased, the 



are flattened, the abdomen narrowed, and the piloe obsolescent In fact, during 

 form and chat ire produced verj similar to the stouter 



8 ' ith which it w.i itcd. 



