'45 



As far as may be judged from a single radula of each species, its characters, in connection 

 with the conchological ones, are favorable to the specific distinctness of the two forms. 



13. Amphiperas (Radius) deflexum Sowerby. 



SOWERBY. Proc. Zool. Soc. Lond. 1848, p. 136. 



Reeve. Conch. Ie. Vol. XV, Ovulum, fig. 56. 



Weinkauff. Martini-Chemn. Conch. Cab. Ed. II, Vol. V, Ovula, p. 206, PI. 52, fig. 6, 7. 



Tryon. Man. of Conch. Vol. VII, p. 252, PI. 4, fig. S. 



Stat. 98. 6°9'N., 120° 21' E. Sulu Sea. 350 M. Sand. 1 Spec. 

 Stat. 213. Saleyer. Reef. 1 Spec. 



The specimen from Saleyer is a fine, adult one, that from Stat. 98 is worn and partly 

 broken, consequently it remains doubtful; probably washed down. 



14. Amphiperas (Radius) birostre Linné. 



LiNNÉ. Syst. Nat. Ed. XII, p. 1182. 



KlENER. Coq. Viv. Vol. I, Ovula, p. 24, PI. 5, fig. 1. 



Reeve. Conch. Ie. Vol. XV, Ovulum, fig. 45. 



Weinkauff. Martini-Chemn. Conch. Cab. Ed. II, Vol. V, Ovula, p. 200, PI. 5, fig. 22, 23. 



Tryon. Man. of Conch. Vol. VII, p. 253, PI. 4, fig. 10, 11. 



Stat. 164. i°42'.5 S., i30°47'.5 E. Halmahera Sea. 32 M. Sand, small stones and shells. 2 Spec. 

 Stat. 240. Bar.da. 9 — 45 M. Black sand, coral. 1 Spec. 

 . Stat. 273. Pulu Jedan, East coast of Aru-islands. 13 M. Sand and shells. 2 Spec. 



One of the specimens from Stat. 164 is young, the other though by its thickened peris- 

 tome evidently nearly adult is very small, measuring only 23 Mill. in length, those from Stat. 

 273 are typical. 



15. AmpJiipcras (Ncosimnia) secale Sowerby. 



SOWERBY. Species Conchyliorum. Vol. I, Part I, Ovulum, p. 8, fig. 56. 



REEVE. Conch. Ie. Vol. XV, Ovulum, fig. 66. 



WEINKAUFF. Martini-Chemn. Conch. Cab. Ed. II, Vol. V, Ovula, p. 210, PI. 53, fig. 6, 7. 



Tryon. Man. of Conch. Vol. VII, p. 254, PI. 5, fig. 28, 29. 



Stat. 253. 5°48'.2 S., I32°I3'E. Arafura Sea. 304 M. Grey clay, hard and crumbly. 5 Spec. 



The depth at which the specimens have been captured, makes a somewhat exceptional 

 appearance amongst the other species of the genus 1 ); the specimens contain the soft parts and 

 so one may conclude that they will have lived on the collecting-ground. 



The rhachidian tooth (R) of the radula has a broad, angular body, with a rounded basal 

 line, its cusp has one large median denticle and on each side four smaller ones; the lateral 

 tooth (1) has a rhombic shape with a taillike process on the distal side of the body and a long 

 cusp with four smaller ones on the visible distal side of the reflected margin; the uncini have 

 the family-character, the denticles of the outer ones are bifid and trihd. 



1) Those from Stat. 98 probably having been washed down. 



37 



