160 PYRAMIDELLID^E. 



f- 7' 28. O. scALA'Ris*,(Philippi.) N 



Melanin (afterwards Chemnitzia) scalaris, Pliil. Moll. Sic. i. p. 157, 

 t. ix. f. 9. C. scalaris, F. & H. iii. p. 251, pi. xciv. f. 5, and (animal) 

 pi. FF. f. 5. 



BODY nearly clear frosted-white, or pale red-brown [of a 

 brownish-madder hue (F. & H.)] : mantle having a small cloven 

 fold at the upper angle of the mouth of the shell : snout deeply 

 notched in front, with the segments gently curved : tentacles 

 rather long, strong, and divergent ; they do not quite coalesce 

 at their bases, being separated by a distinct groove which is the 

 continuation of one on the snout from the point where the 

 notch ceases ; terminal bulbs not much developed : eyes black, 

 not very close together : foot short, slightly auricled, and bluntly 

 pointed behind. (Clark.) 



SHELL forming a very elongated cone, moderately solid, 

 opaque, rather glossy: sculpture, numerous laminar longitu- 

 dinal ribs, varying in number from 25 to 30 on the body- whorl ; 

 they are sometimes nearly straight, at other times set obliquely, 

 or curved, occasionally flexuous, and they seldom extend to the 

 base ; their interstices are crossed by tine and more close-set 

 spiral striae, which are often arranged in pairs and cover the 

 base ; no cancellation is produced, because the ribs are always 

 more prominent than the stria3 ; the top whorl is, as usual, 

 smooth : colour pale-yellowish or creamy, with frequently 2 or 

 3 faint tawny bands round the last whorl (one broader in the 

 middle, another below the periphery, and sometimes a third 

 under. the suture) ; the preceding whorls have only the upper 

 band or that and the middle one: spire tapering somewhat 

 abruptly to a rounded point, which forms the nucleus or crown ; 

 this is remarkably prominent, and, although twisted inwards, 

 it exposes nearly the w r hole of the reversed portion of the spire : 

 whorls 8 (exclusive of the nucleus), turreted, convex but com- 

 pressed, and gradually enlarging ; the last occupies about two- 

 fifths of the shell : suture deep, slightly oblique : mouth irre- 

 gularly rhomboidal, owing to the angular shape of the pillar- 

 side ; it is somewhat contracted above and expanded below ; 

 length about a fourth of the spire : outer lip rounded, not much 

 projecting, incurved a little below the periphery: inner lip 

 adhering to the upper slope of the pillar (although scarcely 

 perceptible), straight below, and slightly reflected towards the 

 base, where it shelves inwards: umbilicus or tooth none: oper- 



* Resembling a flight of steps. 



