two Forms of Rissoid Gasteropods. 349 



planis, spiratis, ad suturas acute angulatis, costellis longitudinali- 

 bus tenuibus confertis, interstitiis lineis transversis elevatis decus- 

 satis instructis ; apertura ovata ; peritremate continuo ; labro 

 margine anguste varicoso. 



Hab. Mososeki; 7 fathoms. 



In this rather thin species the whorls are spirate, sharply 

 angulate at the sutures, and furnished with longitudinal 

 riblets. 



6. Onoba patula, A. Adams. 



0. testa ovata, solida, rimata, sordide alba ; spira brevi ; anfrac- 

 tibus 3\, postice acute angulatis, ultimo magno, costellis longi- 

 tudinalibus undulatis et lineis transversis elevatis concinne decus- 

 sato ; apertura oblonga, antice dilatata; labro valde dilatato, 

 margine reflexo, undulato, postice libero et angulato. 



Hab. Yobuko, west coast of Kiusu ; 14 fathoms, mud. 



In this species the lip is greatly dilated and reflexed; the 

 whorls are sharply angulated posteriorly, and there is an elon- 

 gate narrow umbilical chink. 



7. Onoba egregia. A. Adams. 



O. testa subulato-turrita, sordide alba ; anfractibus 6, planiusculis, 

 spiratis, postice rotundate angulatis, lamellis longitudinalibus 

 erectis undulatis, interstitiis transversim pulcherrime striolatis in- 

 structis ; suturis profundis ; apertura aperta, ovali ; peritremate 

 tenui, continuo ; labro subdilatato, margine simplici, undulato. 



Hab. Seto-Uchi; 17 fathoms. Yobuko; 10 fathoms. 



A very charming species, with lamellar, undulating longitu- 

 dinal riblets, and the interstices crossed by fine spiral elevated 

 lines. The aperture is somewhat expanded, and there is no 

 externa] varix on the outer lip. 



8. Onoba lucida, A. Adams. 



0. testa turrito-subulata, alba, tenui, pellucida ; anfractibus 4, con- 

 vexiusculis, lineolis transversis elevatis concentricis confertis or- 

 nata ; apertura ovali, antice integra ; peritremate continuo ; labro 

 margine tenui, varicoso. 



Hab. O-Sima. 



This species resembles 0. bella in form and sculpture ; but it 

 wants the spiral callus at the base of the last whorl, and the 

 conspicuous varix on the outer lip ; it is also much smaller and 

 more pellucid. 



