368 MR. R. B. WATSON ON MADEIRAN MOLLUSKS. [Mar. 18, 



Spiral threads 12 to 13, raised, rounded, shining; those on 

 upper part of body-whorl are thrown out by the ribs into sharp 

 points ; they are generally pretty equally parted by spirally scratched 

 interstices a little broader than themselves ; on the base they are 

 sometimes closer-set, and sometimes are followed by a kind of 

 miniature of themselves occupying half the interstice. The spiral 

 scratchings of the interstices are extremely minute ; and though more 

 distinct than in jB. moniziana, they do not interfere with the gloss of 

 the surface as they do in R. crispa ; about six go to each inter- 

 stice. There is a broad, thick, white labial rib, which is strongly 

 scored across by the spiral threads ; and between these the interstitial 

 scratches are plainly shown ; but all these disappear just short of 

 the mouth, which is edged by a thin and narrow border in advance 

 of the labial rib ; this border is well scored longitudinally. 



Colour orange (whence the name), with a slight dash of brown, in 

 some cases paler, in others darker, but with little variety, and quite 

 uniform in each specimen, except that sometimes, though rarely, the 

 first whorl has a shade more of brown. The labial rib is whiter 

 than the rest of the shell. 



Spire long, very little contracted upwards, rising but slightly in 

 steps, ending in a depressed round apex, which is always higher on 

 the side where the extreme embryonic tip stands up. 



Whorls 4 to 5, fully rounded, of regular increase. 



Suture deep, little oblique. 



Mouth very round, obtusely pointed above and encroached on by 

 the belly ; not open, except a little in front and on the pillar. 



Outer lip much thickened by the labial rib, but on its extreme 

 edge sharp and thin, slightly expanding below. Its exterior profile, 

 as the shell lies on its back, is formed by the labial rib bearing as 

 knobs the ends of the spiral threads. 



Inner lip consists of the projecting edge of the outer lip, which 

 sweeps continuously round ; on the pillar it is a little reflected, and 

 has there a sharp but little-projecting edge, with an umbilical chink 

 behind it ; this chink is generally small and narrow, but is some- 

 times open and trough-like. The callus which carries the pillar-lip 

 across the belly is thin and closely united to the body ; at its 

 junction with the outer lip it seems always, in well-grown specimens, 

 to project a little way out from the body to meet that lip. 



Sh. M. 5. 4. 3. 2. 1. 



L...-080 -027 '033 -018 -013 -008 '007 

 B.. . -042 -023 -03 -04 '03 '02 -013 



Hab. Piedade (Canical), 15 to 35 fathoms ; Ponta de S. Lourenco, 

 25 to 45 fathoms ; Funchal Bay, up to 50 fathoms ; Porto Santo, 

 up to 50 fathoms. 



I have named this shell from its colour. 



Rissoa striata, Adams ; var. lirata, Watson. (Plate XXXIV. 

 fig. 4.) 



ng 



Not in M'Andrew's list. 



