no. 1820. NEW SHELLS FROM BERMUDA— BALL AND BART8CH. 285 



angle. Outer lip thin, showing the external sculpture within; inner 

 lip strongly curved, reflected over the base; parietal wall glazed with 

 a moderately thick callus which renders the peritreme complete. 



The unique type comes from Bermuda, and has seven post-nuclear 

 whorls measuring: Length 2.9 mm., diameter 1 mm. It is in the 

 collection of the Bermuda Museum. 



CERITHIOPSIS IO, new species. 

 Plate 35, fig. 3. 



Shell elongate-ovate, white, with three bands of very dark brown. 

 The first of these bands extends over the posterior row of tubercles 

 on each whorl, the second covers the cord at the periphery, while 

 the third extends over the anterior half of the base. Nuclear whorls 

 decollated in the two specimens before us. Post-nuclear whorls 

 marked with three spiral cords, of which the first is at the summit, 

 the third at the suture, while the second is a little nearer to the first 

 than to the third. In addition to these spiral cords, the whorls are 

 marked with somewhat retractive axial ribs, which are about as strong 

 as the spiral cords, the intersections of the two forming well developed 

 tubercles, while the spaces inclosed between them are strongly im- 

 pressed, rounded pits. The tubercles of the cord at the summit are 

 well rounded; those of the median cord slope abruptly anteriorly 

 and more gently posteriorly, while those of the third cord are trun- 

 cated posteriorly, sloping gently anteriorly. Sutures strongly 

 impressed. Periphery of the last whorl marked by a spiral cord, 

 which is less strong than those on the spire. Base moderately long, 

 well rounded, the posterior half marked by the continuations of the 

 axial ribs, which terminate somewhat abruptly at the insertion of the 

 columella. These ribs render the peripheral spiral cord tuberculated, 

 the tubercles being slightly truncated posteriorly, sloping gently 

 anteriorly, where they disappear at the insertion of the columella. 

 The insertion of the columella is marked by a moderately strongly 

 impressed, spiral line. Anterior half of base marked by ten some- 

 what irregular, raised, spiral threads, which are about as wide as the 

 spaces that separate them, the entire space being marked with 

 exceedingly fine, raised, axial threads. Aperture irregularly rhom- 

 boid, decidedly channeled anteriorly, weakly channeled at the pos- 

 terior angle; outer lip thick, showing the external sculpture and 

 color markings within; inner lip reflected over the base; parietal 

 wall covered with a thick callus which joins the columella and the 

 posterior angle of the aperture and renders the peritreme complete. 



Two specimens of this species were sent by Mr. Haycock, which 

 may be considered cotypes. One of these is in the Bermuda Museum, 

 the other is Cat. No. 221615, U.S.N.M. One of these has six post- 

 nuclear whorls and measures: Length 2.3 mm., diameter 1.1 mm. 



