84 Mr. J. C. Melvill on the 



spirally striate. Outer lip tliin. Columella shining, somewhat 

 reflexed. 



About twelve examples, all similar excepting in coloration. 



Named in honour of the discoverer, Mr. Frederick W. 

 Townsend, of Manora, Karachi. 



Nassa {Ilima) ischna ^, sp. n. (PI. I. fig. 1.) 



iV. testa parva, multura attenuata, apice acutissimo, cinereo-alba, 

 Isete infra suturas et ad medium anfractus ultimi (interdum inter 

 costas solum, interdum uudique)brunneo-fasciata ; anfractibus 9|, 

 quorum 24 apicales albi, vitrei, caeteris longitudinaliter costatis, 

 costis corrugalis, apud ultimum in numero tredeoim, undique 

 spiraUter liratis, ad costarum juncturam gemmuliferis ; labro 

 extus albo, incrassato, intus denticulate ; columella alba, nitida, 

 haud multum incrassata. 



Long. 10, lat. 4 mm. 



Hab. Persian Gulf, near Muscat. 



A small but very striking Nassa, extremely attenuate and 

 acuminate, ashy white, brightly banded just below the sutures 

 and in the centre of the last whorl with brown, this some- 

 times only appearing in the interstices between the ribs, in 

 other examples on the ribs as well, uniformly. The ribs are 

 roughened with the gemmae which appear at the point of junc- 

 ture with the spiral lira?. On the last whorl there are about 

 thirteen ribs. The whorls are about nine and a half ; of these 

 the apical are Avhite, glassy, and shining. The aperture is 

 ovate; outer lip white, shining, thickened, within denticulate ; 

 columella only slightly thickened, white, shining. 



There seems much in common, save for form, between this 

 species and A'', mammillijera f, Melv., also from the Persian 

 Gulf, which I originally designated as belonging to the sub- 

 genus Niotha, Ad. I should now be disposed to place both 

 these forms in Hima, Leach. These subdivisions are in 

 some instances quite misleading, and I iiave found occa- 

 sionally a species that might almost equally well belong 

 to two or three of them. Niotha is characterized as differing 

 from Hima in three salient particulars : — 



(a) In short as against elevated spire. 



{b) Very large callus, compared with a callus only " de- 

 fined." 



(c) Outer lip with no, as opposed to a conspicuous mar- 

 ginal, varix. 



A few examples, in fine condition, occurred. 



* laxfos, thin, attenuate. 



t Mem. Lit. Jv: I'liil. t>oc. Manch. vol. xli. pt. 3, p. 4 (189o-0r). 



