11 2 NUCULID/K. 



lamellosa, cristis binis squamiferis postice radiata. Extremitas 

 rostri postici angusta, biangulata. Margo dorsalis uterque vix 

 declivis ; posticus incurvatus. Labia areas magnse, ltevis, concavae, 

 protrusa. — Peaked elongated-oblong, rather thin, compressed, 

 under an ashy or pale olivaceous ash-coloured epidermis glossy 

 white, concentrically traversed by distant erect lamella?, which ter- 

 minate just before an umbonal ridge that is formed by two crest- 

 like squamose ridges enclosing between them a flattish and nearly 

 smooth area ; intervals of the lamella? unsculptured. Extremity 

 of the moderately yet decidedly shorter anterior side attenuated, 

 and unsymmetrically rounded: hinder side gradually beaked; the 

 tip fine, biangulated, subcentral. Front dorsal slope very slight, 

 plano-convex ; hinder dorsal slope rather slight, incurved, rising 

 at the extremity. Ventral margin arcuatedly rising in front, less 

 so behind, slightly indented before the posterior tip. Escutcheon 

 large, smooth, concave, yet with pouting lips. Lunule linear, 

 smooth, conspicuous. Teeth on either side of the very small 

 triangular cartilage-pit very numerous. — The epidermis is occa- 

 sionally iridescent. A more or less obsolete anterior indented ray 

 is generally perceptible. 



12. L. concinna, A. Adams, f. 54, 55. — T. lanceolata, postice 

 attenuato-rostrata, antice superne subangulata, valde inasquilate- 

 ralis, multum compressa, cute tenui cinereo-virescente induta, 

 concentrice lamellosa ; lamella? superne remotiores. Margo dor- 

 salis anticus rectiusculus, vix declivis ; posticus retusus, leviter 

 declivis. Arese dorsales elongata?, teves, impressse, angulatim 

 circumscripta? ; labiis protrusis. — Lanceolate, very inequilateral, 

 subangulated dorsally in front, attenuatedly beaked behind, rather 

 thin, much compressed, only gaping at the very narrow biangu- 

 lated and scarcely upturned posterior tip, covered witli a thin 

 greenish-cinereous epidermis, devoid of marked anterior indented 

 ray, with a narrow umbonal ridge, which is subspinosely keeled 

 on either side. General surface concentrically lamellated ; inter- 

 vals of the lamella?, which are much more remote on the umboes, 

 and somewhat more distant in front, smooth. Front dorsal slope 

 slight, nearly straight ; hinder dorsal slope rather slight, refuse. 

 Ventral margin obliquely arching upwards in front, convex and 

 moderately rising behind, refuse before the posterior tip. Dorsal 

 areas elongated, smooth, angularly defined, impressed, but with 

 the lips pouting. 



13. L. tencisulcata, Coutlwuy, f. 87. — T. L. permila assi- 

 milis, sed minor, radii impressi fere vel omnino expers, cute lutea, 



