298 MR. K. A. SMITH ON THE [Apr. 1, 



Action semisculptus. (Plate XXIV. fig. 8.) 



Ti^ata ovata, turrita, jjccrva, nitida, nivea, aiu/ustissinte rimaia, 

 siipei'iic lavis, infra medium suhdtstanter trannvernim jjuiijctato- 

 strlata ad hashn coafeftiu&- striata, suleis paucis lonyitudinalibus 

 indistiiictis, cretiutis, diMantihus scidjjta ; anfractus quatuor, 

 leviter cuitve.vi, siitura angaste canulicalata sejuncti ; uptx iiivo- 

 lutus ; ajjertura inverse auriformis, lomjit. totius i jiaullo 

 sa^ierans ; columella anauste rejlexa, plica parva 'prope rimam 

 tnunita. 



Luiitjit. 4 milUin., diain. 2\. 



The spiral transverse punctured strise do not extend above the 

 middle of the body-whorl. The longitudinal narrow and shallow 

 indistinct sulci apparenth' indicate lines of growth. 



Leucotina minuta. (Plate XXIV. fig. 9.) 



Testa minuta, oblomja, alba ; anfracius 5. ^iriniu^ (nucletus) rotaii- 

 datas, iiiiruvtrsas, sjjiraliter llratus, co-teri conuexi, liris tciiui- 

 5tw spiraUbas (in. anfr. penult, circiter 7) instructi,in interstitils, 

 liris 'paido angu.<tioribus, lineis lon</itadinalibus tenuissiinia 

 sculpti ; ujjertura ovata, superne acuminata, infeme cum colu- 

 mella arciuita et dilatata leviter effusa ; plica columella: centralis, 

 distincta. 

 Lon{/it. 2| millim., diam. f . Var. brtvior 2\ loncja, 1 lata. 

 The apex of this interesting species is peculiar, being introverted 

 as it were, and partly enveloped by the succeeding whorl. It is not 

 smooth, as is frequently the case in other species, but obliquely spirally 

 lirate. The raised lines in the grooves between the ridges produce a 

 subpunctate appearance. 



The genera Myonia and Leucotiuu were described by A. Adams 

 in the 'Annals and Magazine of Natural History,' 18(50, vol. v. 

 p. 4Uti. On examining the diagnoses a great similarity is observ- 

 able, and, indeed, with the exception of a slight difference in form, 

 there seems to be very little, if any, distinction. 1 therefore would 

 propose that these genera be united, in which case Leucotina may 

 be retained, Myonia being preoccupied. M. japonica, A. Adams, I 

 have not seen ; but Actceon modesta, A. Adams, Monoptygma casta 

 = M. concinna, both of A. Adams, and Daphnella casta. Hinds, all 

 typical forms of Myonia, have been examined, and they do not offer 

 any characters which -^nll separate them generically from Leucotina 

 niphonensis, A. Adams, L. dianee, A. Adams (described as an Actceon), 

 &c. 



One of the species of this genus, L. casta, A. Adams, has been 

 referred by Watson (' Challenger' Report of Gasteropoda, p. 487) 

 to the section Parthenia of Odostomia ; but this location is not cor- 

 rect, I think — Parthenia^, comprising longitudinally-ribbed shells, 

 being apparently synonymous with Chemnitzia, d'Orbigny, or Tur- 

 honillu, Risso, 18'2(i. Judging from the shell-characters, I should 



1 -This name was proposed by Lowe in 1840. It hail previously (1830) been 

 used by Robiueaii-Desvoidy for a f^cnus of Insects. 



