Mollusca of the Arabian Sea, dec. 91 



A species apparently common, though local, in the Persian 

 Gulf, and probably extending in both a southerly and east- 

 ward direction. It has hitherto been confounded with 

 M. pacijica, Reeve, of which I possess an original type from 

 the collection of the late Sir D. Barclay, Bait., the example 

 figured in Sowb. Thes. Conch, t. ccclxxviii. fig. 630, which 

 exhibits a form more compressed, strongly shouldered, and 

 angulate in the upper portion of each whorl, very rugose, and 

 ribs fewer but more m.arked in proportion. I consider this 

 latter species nearer to the variable M. cadaverosa, Reeve, so 

 abundant in the Philippines, and especially the islands of the 

 Pacific. BJ. Wisemanni, Dohrn, is in size nearer our shell, 

 but the clearly defined and frequent longitudinal ribs, un- 

 varying in all the specimens I have seen, amply distinguish 

 it. I am much indebted to Mr. Sowerby for especially calling 

 my attention to this hitherto neglected species. 



Erato olivaria, sp. n. (PI. I. fig. 9.) 



E. testa arcuato-pyramidata, solida, laete olivacea, apice subconico ; 

 anfractibus quatuor, supernis interdum rugosulis, interdum 

 Isevibus, ultimo anfractu laevi, rapide accrescente, tumidulo, 

 pjMiformi, apud basim paidlum attenuate ; apertura angusta, 

 oblonga; labro exteriore crassiusculo, denticulis quindecim intus 

 praedito, margine columellari, et prsecipue versus basim, ineras- 

 sato, denticulato. 



Long. 6, lat. 3"25 mm. 



Hah. Karachi. 



A few examples of a somewhat solid sraoothish Erato, 

 conspicuous for its bright olive hue ; the apex is subconical ; 

 whorls four, the last being large, pyriform, somewhat attenuate 

 at the base, the mouth narrowly oblong ; outer lip thickened, 

 denticulate within, with fifteen little teeth ; columellar margin 

 thickened, especially towards the base, and then also den- 

 ticled. This species slightly resembles the European E. Icevis, 

 Donovan. 



The only other known smooth species of a uniform green 

 or olive hue is E. prayensis, Rochbrune, from the Cape Verd 

 Islands, but, from description, would seem to differ both in 

 form and lip-characters. 



Natica Ponsonbyi, sp. n. (PI. II. fig. 4.) 



N. testa globosa, anguste sed profunde umbiHcata, solida, l^evi, 

 paullum nitida, albida ; anfractibus 4-5, apicali fere immerso, 

 uigro, caeteris supra suturas castaueo-fasciatis, ultimo anfractu 



