REPORT OX THE GASTEROPODA. 439 



of •which are embryonic ; they are well-rounded and tumid, of slow and regular increase. 

 Suture nearly horizontal, but more oblique towards the mouth, not deep, but slightly 

 channelled. Mouth slightly oblique, nearly semicircular, but a little pointed above, about 

 tbree-fourths of the total height, open, slightly augulated at the umbilical carina, pure 

 white within, but with a very faint tinge of rust at the band. Outer lip open, thickish 

 and blunt, a little flattened above where it leaves the body-whorl; its curve is very 

 equable throughout. Inner lip porcellanous white, straight, little oblique, reverted, 

 thickish, with a minute ledge within the edge of the mouth ; its upper corner has a 

 largish, slightly projecting pad, with a slight shallow channel between it and the edge 

 of the outer lip ; below this pad the inner lip slightly retreats, but at the large white pad 

 which fills the upper part of the umbilicus it advances very prominently, with a strongly 

 defined edge ; below this pad it retreats sharply to the pillar, forming a nick on the left 

 side of the pillar ; below this it is again thickened and expanded at the umbilical carina- 

 tion. Umbilicus funnel-shaped, narrowed rather than defined by the umbilical carina ; 

 it is half concealed and within reduced to a mere pore by the heavy twisted umbili- 

 cal pad. H. 0-43 in. B. 0*45. Penultimate whorl, height 0-11. Mouth, height 0*35, 

 breadth 0"26. 



This species resembles Natica phytclcphas, Reeve, from Australia ; but in that species the spire 

 is not so much exserted, the umbilicus is open, circular, pervious, and spirally lirate. It is perhaps 

 nearest to Natica plicatula, Nuttall, from China, but is much more depressed, has the earlier whorls 

 smaller, and though the umbilicus is like it is much larger though more closed by the interior pad. 

 Natica raynoldiana, Reel., has (?) the same kind of umbilicus, but the front of the body-whorl is 

 shorter and the apex is much finer. 



11. Natica effossa, 1 n. sp. (PL XXVIII. fig. 3). 



Station 161. April 1, 1874. Lat. 38° 22' 30" S., long. 144° 36' 30" E. Port Philip, 

 Melbourne. 33 fathoms. Sand. 



June 3, 1874. Port Jackson, Sydney. 30 to 35 fathoms. 



Shell. — Small, very thin, smooth, white, oblique, with a somewhat raised scalar spire, 

 a large blunt apex, with a wide, deeply excavated suture and a small pervious umbilicus, 

 with a low-set feeble spiral callus. Sculpture: Longitudinals— there are close-set fine 

 hair-like lines of growth. Spirals— there are very superficial scratches and occasional 

 feeble lines over the whole surface, the scratches are distinct on the base and strong 

 within the umbilicus. Colour semi-transparent porcellanous white. Epidermis: none 

 visible. Spire rather raised, scalar. Apex large, but flattened on the very top. Whorls 

 4 in all, of rapid increase, the last is tumid ; the embryonic nucleus has \h whorls, but, 



1 The name was suggested by the excavated suture. 



