220 FISSURELUD.E. 



viridescens, vertice obtuso, ad partem posteriorem posito ; costellis 

 radiantibus, interstitiis baud sequantibus, et striis incrementi or- 

 natis, basi arcuata; aperturee margine crenulato, incisura baud 

 profunda sublaterali, intus in canalem producta. Obs. In the 

 one-sided position of the notch in this one species G. 13. S. does 

 not see a sufficient reason for the erection of a separate genus. 



62. notata (f. 86, S7, 88), Linn. — Ovalis, depressa, cinerea, 

 nigro lineata et maeulata ; apice postico, obtuso ; costis radianti- 

 bus nigris, rugosis, inaequalibus ; margine antico vix emarginato, 

 intus cicatrice inconspicua. Obs. In this species the fissure has 

 been filled up almost or quite to the margin, and is only percep- 

 tible by a slight notch and an inconspicuous cicatrix. 



Genus SCUTUS, Mont/ort. 



ParmophoritS) Scvtellifes, Dascinum> etc. 



Plates XIII., XIV. 



Char. Gen. Molluscum gasteropoduin ; capite proboscidiformi ; 

 tentaculis crassis et subulatis ; oculis in tuberculis ad bases ex- 

 ternas positis ; pallio super testam reflexo ; pedum latera cirro- 

 runi serie instructis ; testa oblonga, sulciformi, depressa, apice 

 dorsali oblique postice inclinato ; aperturse margine antice sinuato ; 

 iinpressione musculari oblonga, postice semicirculari. 



1. elongatus (f. 1, 2, 10, 21), Lamk. — Tenuis, elongata, an- 

 terius integra, striis exiguis radiata; marginibus acutis. Obs. 

 The concentric lines are scarcely waved. The surface is slightly 

 striated. 



2. unguis (f. 19), Linn. — Solida, glabra, utrinque subtrun- 

 cata, striis concentricis inaequalibus impressa, dorsi animalis lon- 

 gitudinem Eequante, marginibus incrassatis. Obs. Very straight, 

 oblong, square at the anterior end, with straight lines of growth. 



3. bkeviculus (f. 6), Blaine. — Solida, glabra, dorso convexo 

 animalis longitudinem non Eequante. Obs. This shell is very 

 much shorter in front than the other species. 



4. corrugatus (f. 4, 7), Reeve. — Elongata, utrinque subro- 

 tundata, dorso piano, striis concentricis validis corrugatis instructo. 

 Obs. Shaped like S. elongatus, but with the concentric lines waved 

 strongly so as to form a corrugated surface. 



