220 BULLETIN 181, UNIT'EiD STATE® NATlOaSTlAiL MUSEUM 



1852. Cyclostoma moricandi Pfeeffer, Zeitschr. Malak., vol. 9, p. 64. 

 1897. Amphicyclotvs moricandi Pfeiffer, Kobei.t and Mollendorff, Nachrb., 

 deutsclien malak, (Jes., vol. 29, p. 139. 



Shell minute, helicoid, bluish white. The nucleus consists of 1.5 

 inflated, well-rounded whorls, of which the first half turn is smooth ; 

 the rest bears 7 slender spiral threads. Postnuclear whorls inflated, 

 strongly rounded. The first half turn bears the continuation of the 

 spiral threads characterizing the nucleus and all the whorls, but the 

 last four turns are marked by rather strong, distantly spaced, very 

 regular scalariform axial ribs. Of these axial ribs 24 are present on 

 the first turn and 30 on the second ; on the remaining quarter of a turn 

 they become gradually much more closely approximated and not quite 

 so regular. In the broad spaces between the axial ribs microscopic 

 incremental lines are present. Suture very strongly constricted. 

 Periphery well rounded. Last whorl decidedly solute. Base openly 

 umbilicated, inflated, strongly rounded and marked by the continua- 

 tion of the axial ribs, which extend over the umbilical wall, and slender 

 raised spiral hair lines, which are of equal strength but not of equal 

 spacing. The operculum is concave on the outside, the edge being a 

 deep groove separating the basal chondroid plate from the outer edge 

 of the lamella. The calcareous lamella consists of about 11 obliquely 

 outward-directed whorls which form a continuous concave surface; 

 they are separated by a mere impressed line and are marked by numer- 

 ous, closely spaced, slender, retractively curved threads. The center 

 of the inner surface is raised into a papilla which has a central pit. 



Of the animal Moricand also says that Blanchet, who sent him the 

 specimens, wrote him that the tentacles were conical and that the eyes 

 were placed at their base. The large specimen here figured has a little 

 more than 4 whorls and measures : Height, 4 mm. ; greater diameter, 

 5 mm. ; lesser diameter, 3.8 mm. 



Type locality : Province of Bahia, Brazil. 



One of the two specimens in the Academy of Natural Sciences of 

 Philadelphia, No. 12955, from Brazil, which were kindly lent to us for 

 study, had a dried animal in it which yielded a radula having the 

 formula 3:4:3:2. 



To the casual observer, this most remarkable little moUusk would be 

 deemed a member of the Oriental genus PlatyrapJile. In shape, nuclear 

 and postnuclear sculpture, as well as in opercular characters, it re- 

 sembles closely certain members of Platyraphe complex from the 

 Philippines, but it lacks the internal sutural tube and puncture of 

 that genus. It will be interesting to see what the soft anatomy will pro- 

 claim when a comparative study has been made. 



