Prof. H. Karsten on the Vegetable Cell. 185 



24. Bulimus IFalli, mihi. 



B. testa acuminato-elongata, gracili, minute umbilicata ; anfractibos 

 octo, minute transrersim striatis; intense brunnea ; apertura parra; 

 columella parum reflexa ; labro simplici. 



Hab. Kalka, Rockhampton (W. S. Wall, jun.). 



Diam. 0-12, alt. 044 unc. Mus. C. 



The same type of shell as B. Tuckeri. 



25. Bulimus OnslouA, mihi. 



B. testa subobtecte perforata, ovata, solidiuscula, striata, albescente 

 vel pallide cornea fasciis crebris transversalibus rufescentibus ; 

 spira conica, obtusa ; sutura profunda ; anfractibus quatuor, parum 

 convexis, striis plurimis semireg;ularibus spiralibus transrersisque 

 sculptis, ultimo rentroso, spiram duplo dimidioque superante ; 

 apertura subverticali, angulato-ovali, iutus pallide plumbea ; peri- 

 stomate simplici, tenui ; margine columellari albido, reflexo, basi 

 adnato. 



Long. 085, diam. 0*60 unc. 



Hab. Dirk Hartog's Island, Shark Bay, Western Australia (Onslow). 

 Australian Museum. 



26. Bulimus Jacksonensts. 



B. testa ovato-conica, im perforata ; anfractibus quatuor, rix conrexi- 

 usculis, glabris, nitidis, ultimo duplo ceteros eequante ; spira ob* 

 tusa ; sutura impressa ; apertura ovata ; labro simplici, corneo 

 pellucidoque ; columella recta. 



Long. 0*14, diam. 005 unc. 



Ilab. Darling Point, Port Jacksoa (King &c.). 



XX. — Histological Researches on the Formation, Development, 

 and Structure of the Vegetable Cell. By Prof. H. Kabsten. 



[Concluded from p. 133.] 



§XL 



Intercellular substance. — Cuticle.-^-Metamorpbotis of the substance of the 

 different membranes of a joint-cell, and their development independently 

 of the operation of a primordial utricle. — Formation of layers by the 

 cell-membrane. — Difference between a cell-membrane and a layer of cell- 

 membrane. — Varieties and causes of the transformations of the originally 

 structureless cell-membrane. — Untenability of the hypothesis of a 

 primordial sac. 



There are two antagonistic hypotheses in histology, viz. that of 

 endogenous cell-formation and that of cell-fission ; but there is 

 a general concurrence on this point — that the walls of existing 

 cells may be thickened in layers. 



By this laminated thickening (of the true nature of which, 

 however, very diflferent conceptions are adopted) the adherents 



