28 NUCULIDJJ. 



costis concentricis crassis subremotis, lirisque radiantibus intersti- 

 tialibus undique decussata. Margo ventrab!s arcuatus, utrinque 

 accHvis. Area profunde impressa, ellijitico-lanceolata, subduplex, 

 superne longitudinabter rugosa, inferne (etiamque lumda aiigusta) 

 transversim costellata. — Very small, peaked-ovate, more or less 

 ventricose, white (without epidermis?), devoid of indented ray, 

 everywhere coarsely ribbed (dorsal areas excepted), itibs longi- 

 tudinal (not concentric) ; their intervals, which are quite as broad 

 as the ribs, and in front, where the latter are somewhat divergent, 

 rather broader, everywhere adorned with radiating lyrae. Sides 

 equal or very nearly so ; anterior end somewhat narrowed and 

 rounded. Posterior side acuminated, the tip bluntly acutangular, 

 subcentral, scarcely upturned. Dorsal slopes moderate; front 

 one convex ; hinder one at first straightish, then convex, eventually 

 incurved. Ventral margin arcuated, rising at both ends. Lunula 

 narrow, barred across ; escutcheon rather large, lanceolated-elliptic, 

 deeply and abruptly impressed, almost double, wrinkled length- 

 ways in the middle, costellated across at the circumference. 

 Hinge-margin very broad : cartilage-pit minute, perpendicular, 

 triangular. 



47. L. Brookei, Ilanlei/, f. 106. — T. minuta, subsequilateralis, 

 late ovato-conica, postice repente acuminata vixque recurvata, 

 ventricosa, eburnea, radii impressi expers, undique concentrice 

 costata ; interstitia costarum angustarum pequaliter lata, in medio 

 laevia, utrinque creno-lirata. Margo dorsalis antice brevis, satisque 

 declivis ; postice rectiusculiis, declivis; ventralis conspicue ar- 

 cuatus, postice rectior multuraque acclivis. Area magna, plica 

 umbonali dejircssa creno-costuta delinita. Lunula sublsevigata, 

 sulco circumscripta. — Minute, rounded ovate-conic, tumid or ven- 

 tricose, glossy ivory-white, barely gaping even posteriorly, devoid 

 of indented ray or raised umbonal ridge, concentrically ribbed 

 throughout (dorsal areas excepted) ; ribs narrow, prominent, nu- 

 merous, only as broad as the intervals, which are smooth in the 

 middle and rather obscurely creno-lyrated at each extremity. 

 Sides very nearly equal ; anterior one the shorter, peculiarly broad, 

 rounded ; posterior one abruptly and sharply acuminated, its ti]) 

 very short, subcentral, scarcely, if at all, recurved. Front dorsal 

 slope short, plano-convex, rather decided : hinder dorsal decided, 

 straightish. Ventral margin peculiarly arcuated, straighter and 

 mucli rising behind. Lunule detined by a sulcus, either smooth, 

 or with only fine raised wrinkles : escutcheon large, defined by 

 the creno-costated projection of the posterior ridge. Teeth rather 

 numerous on either side. — Of this little Leda I have seen but 



