Mr. A. Adams on new Mollusca from Japan. 301 



Genus MUCRONALIA, A. Adams. 



Testa pupiformis, ovato-oblonga, apice subito mucronata ; anfractibus 

 mucronis tribus perparvis ; anfractibus normalibus quinque pla- 

 natis, ultimo ad basin rotundato. Apertura oblongo-ovalis, antice 

 dilatata et producta ; labio simplici ; labro arcuato. 



This curious genus seems to be compounded of Leiostraca and 

 Stylifer, but is not variced or compressed like the former, and 

 is not unicolorous and parasitic like the latter. The texture is 

 unlike that of Sty lifer, and resembles that of Eulima ; and the 

 structure of the mucro does not resemble that of the pointed 

 apex in Stylifer. 



Mucronalia bicincta, A. Adams. 



M. . testa albida, subpellucida, nitidissima, fascia rufa ornata ; anfractu 

 ultimo bicincto. 



Hob. Straits of Korea, off Mino-Sima ; dredged from 63 fa- 

 thoms. 



Genus MORCHIA, A. Adams. 



Testa oblique ovata, late umbilicata, depressa, superne convexa, in- 

 ferno plana ; anfractibus subito crescentibus, ultimo diiatato ascen- 

 dente alios involvente usque ad apicem. Apertura oblonga, obliqua, 

 subhorizontalis, infra dilatata, supra angustata ; peritremate con- 

 tinuo, incrassato. 



M. obvoluta, A.Adams. 



M. parva, opaca, alba, ad peripheriam angulata, striis increment! con- 



fertis ornata ; umbilico patulo, ad suturas crenulato. 

 Hob. Tsu-Sima, Straits of Korea. 



This curious little genus most nearly resembles Teinostoma ; 

 but the base is not covered with a callus, and the mouth is not 

 produced. The last whorl embraces the others, as it does in 

 Neritula or Cyclops. Both Morchia and Teinostoma, however, 

 together with Vitrinetta, are not nacreous, and would seem to 

 associate themselves rather with Adeorbis and Cyclostrema than 

 with Ethalia among the Umboniina, as Mr. P. P. Carpenter be- 

 lieves. The only specimen obtained was dredged from 26 fa- 

 thoms, about a quarter of a mile from the shore, in Washington 

 Sound, off Tsu-Sima, a very lovely island in the Straits of Korea. 

 The bottom was coarse sand and broken shells. 



The genus is named after M. 0. A. L. Morch, author of 

 c Prodromus Faunae Molluscorum Gronlandise/ and a man " in 

 advance of his age." 



Genus ZEIDORA, A. Adams. 



Testa oblonga, dorso convexa, apice postice deflexo, superficie can- 

 cellata sulco mediano antice in fissuram desinente instructa. 



