— 384 — 



oblique cm-vatns; ventralis late arcuatus utriiique adscendens ; 

 umbones subacuti, paulo elevati, circiter in ^/^ long. collocati; 

 latus internuni album, nitidum ; cardinis margo aliquanto in- 

 crassatus, fossa obliqua ligamentum continente postice munitus ; 

 impressio musculnris antica elongata, postica brevior, rotundata. 

 Long. 15., alt. 8,5, crass. 7 Mm. Smith. 



Montacuta cyliudracea Smitli Rep. Challeuger Lamellibr. p. 206 

 T. 12, F. 4. 



Hab. in abyssis oceani atlantici borealis. 



5. Genus Lepton Turton. 



T. aequivalvis, suborbicularis, compressa, vix bians; liga- 

 mentum internuni; cardo dente primario simplici 1 lateralibus- 

 que fortibus 2 in utraque valva. 



1. Lepton squamosum Montagu. T. subangulato- 

 ovata, valde compressa, tenuis, semipellucida , nivea, punctis 

 impressis peculiariter sculpta, antice et postice subtruncata 

 angulis rotundatis; umbonibus parvis vix antemedianis ; cartilago 

 triangularis, minutus; cardo typicus. — Long. 11 — 12 Mm. 



Soleu squamosus Montagu Test. Brit. I p. 565. — Forbes et Han- 

 ley II p 98 T. 36, F. 8. 9. — Sow. III. Ind. T. 6, F. 9. — Jeff- 

 reys Br. Conch. II p. 177 T. 31, F. 2. - Weiukauff Mittelra. 

 p 181. - Locard Cat. p. 472. — Jeffreys Pr. Z. S. 1881 p. 694. 



Psammobia puuctura Browu III. Gouch. T. 16, F. 7. 

 Hab. mare mediterraneum et oceanum atlanticum medium. 



2. Lepton nitidum Turton. T. subrhomboideo-ovata, 

 compressiuscula, mediocriter solida, irregulariter concentrice 

 striata, ad umbones tantum punctis impressis sparsis notata, 

 alba vel palHde lutescens, epiderniide nitida prismatica tecta, 

 umbonibus prominuhs fere medianis; cardo arcuatus, ^l^ ambitus 

 occupans, dentibus quam in L. squamoso fortioribus magisque 

 approximatis. — Long. 2,5 Mm. Variat laevis et punctis undi- 

 que sculpta. 



Lepton nitidum Turton Dith. br. p. 63. — (Kellia) Forbes et Hanley 

 II p. 92 T. 36, F. 3, 4. - Sow. III. lud. T. 5, F. 10. 11. — 

 Weinkaiiff Mittelni. p. 181. — Jeffreys Br. Couch. IIp. 198T. 31, 

 F. 3. - Pr. Z. S. 1881 p 694. 

 Var. convexa, punctis notata: 



Lepton couvexum Alder et Hancock Cat. North. p. 93. — Forbes 

 et Hanley II p. 102 T. 3«, F. 10. 

 Hab. mare mediterraneum et oceanum atlanticum. 



3. Lepton (Neolepton) sulcatulum Jeffreys. T. 

 fere orbicularis, compressiuscula, tenuis, liris regularibus con- 

 centricis hneisque subtihoribus radiantibus sub lente tantum 

 conspicuis sculpta, pellucido-alba epidermide cutacea; marginibus 

 rotundatis, dorsah utrinque dechvi, uinbonibus leviter i^rominuhs, 

 versus extremitatem breviorem inchnatis ; cardo sat fortis, fovea 

 cartilaginis parum profunda, dentibus primariis 1, lateralibus 2 



