298 MR. E. A. SMITH ON THE [A-pr. 1, 



AcTiEON SEMiscuLPTUS. (Plate XXIV. fig. 8.) 



Tcsia ocatu, turrlta, parva, nitida, nivea, auifustissintc' riinata, 

 siiperue hwis, infra medium sahdistanter transvemim puiuctato- 

 striata ad husim coafertius striata, sulcis paucis lonyitudinalibtis 

 indislinctis, crenatis, dista ntihus sctdpta ; anfractus quatuor, 

 leviter conve.vi, sutura anguste canaliculuta sejuncti ; apex invo- 

 lutus ; apertura inverse auriformis, longit. totius i paullo 

 superans ; columella anmiste refiexa, plica parva 'jjrope rimam 

 munita. 



LoiKjit. 4 inillim., diam. 2|. 



The spiral transverse punctured striae do not extend above the 

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

 indistinct sulci apparently indicate lines of growth. 



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



Testa ■minida, ohlomja, alba ; anfractus 5. primus {nucleus) rotun- 

 datus, inirot'ersus, spiraliter liratus, anteri coiivexi, liris teiud- 

 bus spiraUhus (i nanfr. penult, circiter 7) instructi,iit iiiterstitils, 

 liris paulo angustiuribus, linein longitadinulibus teHuissimis 

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

 mella arcuata et dilatata leviter effusa ; plica columellce centralis, 

 distincta. 

 Longit. 2| millim., diam. |. Var. hrevior 2\ longa, 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. Tlie raised lines in the grooves between the ridges produce a 

 subpunctate a])pearance. 



The genera Myonia and Leucotina were described by A. Adams 

 in the ' Anuals and ^lagaziiie of Natural History,' 1860, vol. v. 

 p. -I0(i. Ou examining the diagnoses a great similarity is observ- 

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

 there seems to be very little, if any, distinction. I therefore Avould 

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

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

 have not seen ; but Actceon modesta, A. Adams, Monoptygmu 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 will separate them generically from Leucotina 

 niphonensis, A. Adams, L. diance, 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 I'artheniu 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, 182(i. Judging from the shell-characters, I should 



' This name was proposed by Lowe in 1840. It had previously (1830) been 

 used by Kobiuenii-Desvoidy for a genus of Insects. 



