PLACOSTVJLL'S, NE\V CALEDONIA. 35 



Group of P. fibratus. 



Tliis is the most prolific New Caledonian group in species and vari- 

 eties. The latter are apparently endless ; and as no distinction has 

 yet been made behv.een individual variations and racial divergence, 

 the subject is in almost inextricable confusion. Milton's line " All 

 hope abandon ye who enter here " serves as well for those entering 

 upon the study of these Placostyles as in its original application. 

 Only very extensive local series collected by an observant and careful 

 naturalist can illuminate this subject. 



P. ALEXANDER (Crosse). PL 13, figs. 1,2; pi. 14. figs, 6, 7, 8. 



Shell imperforate, ovate-conic, thick, strongly compressed from 

 front to back, the two sides subangular ; white under a reddish- 

 chestnut cuticle ; smoothish or irregularly wrinkled-striafe. Whorls 

 6, the last large, much wider, flattened. Aperture large, whitish- 

 yellow within, the peristome pale orange-yellow ; outer lip reflexed, 

 strongly thickened, slightly simiated within, above ; columella thick- 

 ened, bearing two low callosities. Length 85, diam. 50 mill. 



Length 103, diam. Go, length of aperture G9 mill, (largest seen). 



Length 78, diam. 51, length of aperture 52 mill, (smallest seen). 



New Caledonia : Inn, iie/ir < hiy<ip ( Wngap') ; also at Kanala (?) 



Bulnitus ale.r<.inder CROSSE, Revue Zoologique, (2), vii, pp. 34, 

 83, pi. 4, f. 2, 3 (1855) ; Journ. de Conchyl. 1864, p. 108 GASSIES, 

 Faune Conch. N. Caled. i, p. 42, pi. 3, f. 1 ( 1863). Pi- R. Monogr. 

 iv, p. 369; vi, p. 13; viii, p. 18 (varieties). 



Placostyhis alexander KOBELT, Conch. Cab. Placosfyhts, p. 27, 

 pi. 7, f. 1, pi. 8, f. 1 (1891). 



Var. PROCERULA : Bvlimus n/<',nti/</er, var. a. CROSSE, Revue 

 Zool., p. 34, 83, pi. 4, f. 1 (1855). GASSIES, Faune, i, p. 43, 1863. 

 Bui turns a/exander, rar. b. CROSSE, Journ. de Conchyl., xii, p. 

 109 (1864) GASSIES, Faune ii, p. 74 (1871.) B. a. \tir.procerula 

 PKK., Monogr. viii, 18. Placostylus alexander var. procerula KOB- 

 ELT Conch. Cab., Placostylus, p. 29. 



Var. OUAGAPENSIS ; Bulhnus alexander, var. g, CROSSE, Journ. 

 de Conchy]., xvii, p. 179 (1869). var. ottayapensis PFR., Monogr. 

 viii, IS.Placostyl/ts alexander var. ouaguppnsif, Kobelt, Conch. Cab. 

 Pfacostyhis, p. 29. 



Var. CRASSA : B. alexander var. d CROSSE, Journ. de Conchyl. 

 xviii, p. 243, 414 (1870). GASSIES, Faune Conch. Nouv. Caled., 



