JLYANASSA. 61 



Its movements are very active, and it collects in numbers about 

 dead crabs and other marine animals, on which it feeds. Inhabits 

 all our muddy shores, preferring situations not exposed to the 

 surf of the open sea; such as inlets and extended flats which 

 are drained at low tide. It is found abundantly at the con- 

 fluence of fresh and salt water, where the ' taste is merely 

 brackish. No shell of equal size is so abundant, on the whole 

 Atlantic shore. Specimens from Florida vary only in being 

 smaller, more olivaceous, and by having a thick, broad callus 

 over the pillar. The younger shells are most likely to be col- 

 lected, because the old ones become very much eroded and 

 defaced, and a jrreenish mould-like plant vegetates abundantly 

 upon them. Very few, therefore, of the shells usually collected, 

 have the lines on the interior of the outer lip. Kiener's figure 

 (fig. 348 , N. oliuaeformis, represents a young shell* The ova- 

 capsules are laid during April and May, are of transparent 

 corneous texture, singly attached to the inside surface of a valve 

 of Mactra, or the inner face of the nidus of Natica ; they are 

 deposited in vast numbers, completely covering the object to 

 which they are attached and crowded together promiscuously 

 (fig. 349)' 



N. MELAMOIDKS. Reeve. PI. 18, fig. 350. 



Smooth, thread-margined around the upper part, striated near 

 the apex, last whorl grooved at the base. Thin, dark olive, 

 interior purple-black. Length, -85 inch. 



Moreton Bay, Australia - Strange. 



Reeve remarks : This species, like N. obsoleta, has a charac- 

 teristic fresh-water aspect like that of a Mclania. I have not 

 seen it. 



N. NIGELLA. Reeve. PI. 18, fig. 351. 



Dark brown, without and within, lip with an exterior varix. 



Length. -4 inch. 



New Zealand. 

 N. NUCEA, Pease. PI 18, tig. 352. 



Dark chocolate ; closely reticulated ; lip with exterior varix. 



Length, 12 mill. 



Caroline Isle*. 



* Gould, Invert. Mass. , Binney's edit., 8fi2. 



