MUSEUxM OF COMPARATIVE ZOOLOGY. 43 



lamellfe are arranged with a regular irregularity (which gives a shagreened 

 appearance to the sui'lace) between the carina;, and are still coarser and more 

 elevated over the threads near the suture, forming there a double row of scales 

 partly obscuring the suture, which is nevertheless rather deep. Alt. of last 

 whorl, 10.0. Lat. 13.0. Alt. of aperture, 5.5. Lat. of same, 6.25 mm. 



Off Cuba, Pourtales, in 200 fms. 



The single specimen taken, though destitute of the apical whorls, seemed 

 too remarkable to leave undescribed. It has a general resemblance to some of 

 A. Adams' species of Turcica from Eastern seas, but has a j^eculiar and re- 

 markable sculpture, and wants the teeth on the pillar. 



Margarita iris n. s. 



Shell thin, brilliantly nacreous, inflated, depressed-conical, five-whorled ; 

 spire obtuse ; nucleus polished, smooth, very minute ; remainder of shell 

 sculptured with fine revolving lines, subequal, about as wide as the inter- 

 spaces, about eighteen at the beginning of the last whorl ; these are crossed 

 by slight plications, beginning near the suture, becoming nodulous on a single 

 prominent thread a little way from the suture (which is thus made to appear 

 somewhat channelled), becoming faint about the middle of the upper side of 

 the whorl, and entirely disappearing before reaching the periphery ; the re- 

 volving lines are fainter on the rounded base ; the umlnlicus is wide and 

 funnel-shaped, bordered by a strong keel with about twenty-five rounded 

 nodules, the inner walls of the umbilicus Avith strong revolving lines deli- 

 cately reticulated by the lines of growth. The whorls are rounded, with no 

 carina at the periphery; the pillar thin, arched, not reflected ; the aperture 

 nearly round, but angulated above by the sutural thread, and below by the 

 umbilical keel ; edges simple, not thickened ; operculum thin, corneous, 

 multispiral ; shell nacreous, with delicate suffused splashes of brown. Alt. 

 5.0. Maj. diam. 5.5. Diam. of aperture, 2.0 ; of umbilicus, 2.75 mm. 



Sand Key, 119 fms. 



Margarita maculata n. s. 



Shell in general form and sculpture much resembling the last, but without 

 the nacreous coloring, stouter and coarser in every respect. Whorls five, the 

 revolving threads on the upper side of the whorls only seven in number (on 

 the last whorl), of which the inner two are crenulated by the radiating plica- 

 tions which otherwise are visible only as radiating threads in the interspaces, 

 the base rounded with nine flattened revolving ril;s separated only by incised 

 lines and crossed by delicate lines of growth. The umbilicus much smaller 

 than in the last, bordered by two nodulous ribs with a remarkably deep groove 

 between them ; aperture as in the last, but not so distinctly angulated ; shell 

 variously painted with Ijrown on a yellowish white ground ; one specimen has 

 five distinct brown patches on the upper side of the last whorl, another has 

 more numerous radiating brown streaks ; the base is whitish, and in adults 



