REPORT ON THE GASTEROPODA. 617 



September 8, 1874. Flinders Passage, Cape York, North-east Australia. 7 fathoms. 

 Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. Wednesday 

 Island, Cape York. 8 fathoms. Coral mud. 



Habitat. — The Philippines, Indian Ocean, and West Indies (v. Martens). 



This species is marked with a note of doubt, for there are some features of very marked dis- 

 tinction between the solitary Challenger specimen and Sowerby's species ; in particular, there ia a 

 very great and sudden narrowing, lowering, and multiplication of the ribs on the last whorl, a 

 feature notably present in Rissoina andamica, Nevill. The shell is also much smaller than Rissoina 

 reticulata, Sow., but size hardly reckons in this very variable genus, and Sowerby's species, in par- 

 ticular, presents great differences, both in size and sculpture. 



6. Rissoina triticea, Pease. 



Rissoina triticea, Pease, Proc. Zool. Soc. Lond., 18G0, p. 438. 



Rissoa triticea, Reeve, Conch. Icon., voL xx. pi. si. fig. 102. 



Rissoina triticea, Weinkauff, Conch. Cab. (ed. Kiister), p. 72, sp. 93, pi. xv.b. fig. 3. 



July 29, 1874. Levuka, Fiji. 12 fathoms. 



Habitat. — Pacific Ocean (Pease) ; Andainans, Ceylon, Aden, Mauritius (Nevill) ; Red 

 Sea (Sickeli). 



7. Rissoina scalariformis, n. sp. (PL XLVI. fig. 6). 



July 1875. Reefs off Honolulu, Sandwich Islands. 40 fathoms. 



Shell. — Very high and narrow, conical, scalar, obliquely ribbed and very faintly 

 spiralled, with a tall sharp apex, shortish whorls, an impressed suture, and a short broad 

 rounded base, which in front is minutely constricted and bordered with a fine cord. 

 Sculpture : Longitudinals — the whorls are crossed by narrow, raised, sharp, fine, rather 

 remote straightish riblets, which, continuing to the base, run down the spire from whorl 

 to whorl, a little obliquely toward the left ; of these there are on the last whorl 12 or 13 ; 

 the last forms a distinct but not powerful varix round the mouth. Spirals — the interstices 

 of the ribs are scratched with very faint little furrows ; round the point of the base is a 

 sharp furrow and cord. Colour white. Spire high and narrow, with very slightly convex 

 profile-lines, scalar. Apex consists of four smooth embryonic whorls, forming a tall 

 conical top, of which the suture is very slightly impressed, and the extreme tip is minute, 

 prominent, and rounded. Whorls 8^ in all ; they are rather short, shouldered above, 

 below the suture convex, but a little irregularly so. Suture very oblique, broadly 

 impressed. Mouth almost semicircular, small, nearly direct. Outer lip sinuated above 

 at its junction and at the point of the pillar, between which with an advancing and 

 sharp but varixed edge it curves equably round. Inner lip strong, and spread out on the 



(ZOOL. CHALL. EXP. — PART XLII. — 1886.) Tt 78 



