1879.] MR. E. A. SMITH ON MOLLUSCA FROM JAPAN. 18/ 



from the Persian Gulf (fig. G). The Japanese examples (fig. 6'a) differ 

 in a slight measure : they are a trifle narrower, have a very'sli"-htly 

 more elongated canal ; and the apex is brown instead of pale viofet as 

 in the typical form. In sculpture and colouring they are identical. 



12. Pleurotoma niponica. (Plate XIX. fig. 7.) 

 ^ Shell shortly fusiform, light brown : whorls GJ ; nucleus consist- 

 ing ot ]o, rather large, globose, glassy shining ; tie four whorls fol- 

 lowmg strongly keeled around the middle, concave above, with two 

 or three fine spiral lirse, and also concave below the carina, margined 

 at the upper and lower boundaries by a fine thread-like lira arcu- 

 ately or flexuously elevately striated above the carina, and obliquely 

 but in an opposite direction, beneath it ; the last whorl encircled be- 

 neath the principal keel by about teu lirse, whereof the uppermost is 

 the stoutest, the rest gradually becoming finer towards the base • the 

 interstices between them crossed by elevated strice or lines of incre- 

 ment. Aperture small, brownish, occupying about three sevenths 

 of the entire length of the shell ; slit situated in the concavity above 

 the principal carination ; columella a little convex or prominent in 

 the middle, and oblique below it ; canal short, scarcely recurved 



Length 7 millims., width 24. 



Hab. Station 21. 



This pretty shell is recognizable by the strong central keel to the 

 whorls, which are excavated above and below, and the raised striaj 

 on the upper portion are obliquely flexuous towards the ri^^ht whilst 

 those below the carina are obliquely straight and inclined to the 



13. Pleurotoma difficilis. (Plate XIX. fio-. 8.) 



Shell shortly fusiform, brownish horn-colour. Whorls nearly flat 

 strongly keeled a little below the middle, and above at the suture' 

 with one or tv.'o thread-like spiral lirse in the spaces between these 

 two carma) and between the subcentral one and the suture below it ■ 

 hues of growth moderately distinct, raised, flexuous, and more or 

 less obhque ; nucleus (or the three apical whorls) smooth, glassv, 

 shining, convex; the fourth also convex and coarsely obliqueiy 

 costate; last whorl encircled by about teu coarsish lira?, whereof the 

 tliree uppermost are equal in size to the submedian carina of the 

 upper whorls, which falls just above tliem on this volution ; the in- 

 terstices between them coarsely striated by the lines of growth Aper- 

 ture small, occupying three sevenths of the entire length ; columella 

 brown, coated with a smooth enamel, oblique below the middle • slit 

 above the submedian liration ; canal short, very little recurved. Ooer- 

 culum ovate, pointed at the base ; nucleus apical. '' 



Length 7 millims., width 2^. 



Hab. Stations 21 and 27. 



Of this species there are two specimens in the collection. la both 

 there are two fine thread-like lirffi in tlie interstice between the upper 

 and submedian keels on the last two whorls ; but the upper one gra- 

 dually becomes obsolete on ascending the spire. The upper of the 



