REPORT ON THE GASTEROPODA. 115 



oval mouth and a large funnel-shaped pervious umbilicus. Sculpture : Longitudinals — 

 above the canal the surface is distantly, radiatingly, and curvedly undulated (like allaliotis), 

 with minute, sharp, close-set threadlets in the intervals ; below the canal there are high, 

 narrow, distant, very curved ribs, which begin feebly below the canal-ridge, and die 

 out at the edge of the umbilicus. Spirals — the old canal rises on a rounded and 

 very prominent ridge, which is perpendicular on the outer and elevated on the inner 

 side ; the canal itself is not depressed, but is very strongly concavely scored. This 

 ridge lies between the suture and the periphery, rather nearer to the latter, and forms 

 a crest to the whorls. Above this ridge the slightly depressed surface is scored with 

 very fine threads, parted by little rounded furrows of about twice their breadth ; below 

 the canal - ridge these spiral threads are stronger, and give a serrated crest to the 

 longitudinal riblets. Spire scalar, but very depressed, the square steps of the whorl 

 edges being very short. Apex small, forming a flat, square-edged coronet, with a slightly 

 depressed minute tip. Whorls 3^ to 4, flat or slightly concave above, highly and squarely 

 keeled by the canal-ridge, below which they are very slightly constricted ; after this they 

 are tumid to the periphery and on the base. Suture angularly impressed. Mouth narrowly 

 oval, very oblique, largish. Outer lip descending and inflected above, very regularly 

 curved, deeply cut by the fissure, slightly patulous towards the lower outer corner. Inner 

 lip very shortly and thinly appressed on the body between the periphery and the edge of 

 the wide-open pervious umbilicus. On the pillar it is barely expanded, is very thin, and 

 runs straight but very obliquely to the point of the base. L. - 048 in. B. 0*065. Mouth, 

 length 0-033, breadth 0-033. 



This is one of the most beautiful species of this very beautiful genus. Its sculpture and form 

 are very marked. 



5. Scissurella declinans, n. sp. (PI. VIII. fig. 2). 



Station 185b. August 31, 1874. Lat. 11° 38' 15" S., long. 143° 59' 38" E. Raine 

 Island, Cape York, North-Eastern Australia. 155 fathoms. Coral sand. 



Shell. — Square above and tumid below, very delicately, sharply sculptured, with a short 

 scalar spire, a minute tabulated apex, an angulated suture, descending mouth, 1 and a large 

 shallow funnel-shaped carinated umbilicus. Sculpture : on the last whorl there are very 

 fine, sharp, close-set, curved, radiating threads, which on the upper whorls are strong riblets ; 

 between them the whole surface is finely, closely, microscopically scored with hair-like 

 lines of growth. Spirals — the whole shell is delicately marked with very fine, regular, 

 rather distant threadlets ; a little way below the suture and within the periphery is a sharp, 

 narrow keel formed by the upstanding edges of the old canal-ridge. Colour dull hyaline. 



1 Whence the name. 



