vriEORBis. 257 



this species the umbilicus is open and the peromphalus obtusely 

 keeled ; the whorls are radiately striated. 



12. promixula (pi. 256, f. -23, 2 I). A. A,!.— Testa discoidalis ; 

 spira elatiuscuki; alba, subdiaphana, nitida, striis incrementi 

 oraata ; anfractibus rapide crescentibus, ultimo ad peripheriam 

 rotundato; umbilico mediocri, margine carinato; labro producto. 

 Obs. In this species the spire is conical and more raised than is 

 usual in this genus, and the margin of the umbilicus is keeled. 



13. depressa (pi. 250, f. 14, 15), A. Ad. — Testa discoidalis; 

 spira planata ; alba, vix opaca, radiatim striata ; anfractibus ra- 

 pide crescentibus, ultimo ad peripheriam rotundato; basi rugulis 

 radiantibus ornata; umbilico patulo, margine valde rugoso-cre- 

 nato ; labro mediocri. Obs. This is a very depressed species, 

 very similar in form to A. plana, but the aperture is more circu- 

 lar and not so oblique as in that species, and the size also is 

 much less. 



14. patruelis (pi. 256, f. 35, 36), A. Ach— Testa ut in A. 

 Japonica discoidalis, sed spira elatiuscula; alba, nitida, semipel- 

 lucida, radiatim striata ; anfractibus regulariter crescentibus, 

 convexiusculis, ultimo ad suturam vix angulato, ad peripheriam 

 rotundato; umbilico angusto, margine carinato ; labro mediocri. 

 Obs. This species has resemblances to several others, but cannot 

 properly be affiliated to any ; the last whorl is slightly angulated 

 at the suture, and the margin of the umbilicus is carinate. 



15. corniculum (pi. 256, f. 29, 30), A. Ad. — Testa ovato-dis- 

 coidalis, tenuis, nitida, subdiaphana, radiatim minutissime striata; 

 anfractibus rapide crescentibus ; umbilico angusto, margine valde 

 carinato; labro producto. Obs. An orbicular turbinate thin 

 species, with shining whorls and a narrow umbilicus. 



16. sutoralis (pi. 256, f. 27, 28), A. Ad.— Testa ovato-dis- 

 coidali ; spira prominula; albida, tenuis, semipellucida, striis 

 incrementi radiatim ornata; anfractibus rapide crescentibus, prope 

 suturas subcarinatis, ultimo ad peripheriam subangulato ; suturis 

 canaliculars ; umbilico angusto, margine rotundato ; labro me- 

 diocri. Obs. A somewhat globose species, with the sutures deeply 

 impressed. 



17. nanula (pi. 256, f. 31, 32), A. Ad. — Testa ovata, sub- 

 convexa, tenuis, semidiaphana, nitida; anfractibus rapide cres- 

 centibus, convexiusculis, ultimo subventricoso ad peripheriam an- 

 gulato; umbilico angusto, margine rotundato; labro mediocri. 



VOL. III. 2 K 



