142 Zoological Society. 



lippine Islands," was communicated by H. Cuming, Esq., Correspond- 

 ing Member, who exhibited specimens to the Meeting in illustration 

 of the descriptions. 



The longitudinal diameter of the Navicella described in this cata- 

 logue has been taken from the anterior to the posterior side, and the 

 transverse diameter ft-om the summit to the base of the external 

 opening, in its broadest part. 



1. Navicella Janelli, Recluz, Revue Cuvierienne, 1841. p. 376. 

 No. 9. 



Var. a, Testd ellipticd, convexd, crass'msculd, vix cancellatd, lineis 



nigris reticulatd, interstitiis lutescentibus. 

 Var. /3. T. lineis nigris superne reticidatis, antice remotiuscidis, sub- 

 cequidistantibus ; apertiird margine cinereo-iiigrescente, in fundo 

 aurantid, interditm nigro-muculatd, 

 Var. y. T. dorso nigro laff pictd et mactdis concoloribus variegatd, 

 antice lineis lugris radiatd , postice dense Uneolatd ; labio lateraliter 

 emai'ginato, medio subproducto ac rectiuscido. 

 Var. ^. T. lutescente, dorso transversim late et remote nigro undatd ; 



zonis interdum antice conico-angulatis. 

 Var. e. T. orbiculari, dorso nigerrimd, maculis lutescentibus sparsis 

 notatd, margine breve lineatd, postice lateraliter, interdum luteo- 

 viridescente ; aperturd margine cinereo-nigrescente. 

 Dimensions.— Y AX. a, 1-80 poll, longa; 1-28 ad 1-40 lata; 0'76 

 adO-80 convexa. Var. e, long. 1-20 ad 1-40; lat. 0*96 ad I'OS; 

 conv. 0-48 ad 0-52 poll. 



Hab. ad Insulas Philippinas. Var. a and y from Agoo, province of 

 Pangasinan, island of Lucon : on stones in a rapid river. The var. 

 ft, S, and e, from Iba, province of Sambales, island of Lucon : on 

 stones in a deep river. 



The only difference I find between the varieties brought from the 

 Philippine Islands and those from Guam (of which I have only been 

 able to examine a single specimen) is, that the former are rather more 

 solid and more convex. As to form and colour, they are too variable 

 to dwell upon. 



The operculum of this Navicella has particular characters, which 

 it is important should be known, as confirming the specific value of 

 this shell. 



Operculum almost square, rather longer than broad, subconvex 

 above, of a light bluish black mingled with flesh-colour, striated upon 

 the surface and upon the anterior side, divided by a broad and shal- 

 low canal, ending in a deep and wide anterior notch, which is cut 

 square at the base. The canal and notch are bounded on the right 

 by a smooth, linear, flesh-coloured rib, which is a little prolonged 

 and truncated at the end with a furrow throughout its length. The 

 left side of its inferior surface is striated above, sinuous at the margin 

 and finely denticulated at its base, which is of a rosy red. 



2. Navicella variabilis. N. testd ellipticd, striis vix sub lente can- 

 cellatd, lineolis transversis vndulatis obsoletisque scejriiis conflneii- 

 tibus olivaceis et maculis lutescentibus nigrescente antice obumbratis 



