1884.] OF THE 'CHALLENGER' EXPEDITION. 2/5 



Helix (Patula) stokesi. (Plate XXIII. figs. 17-17 b.) 



Shell very depressed, moderately umbilicated, obtusely angled at 

 the periphery, pale yellow, irregularly spotted and variegated with 

 reddish subradiating markings above, and dotted and streaked beneath 

 with a lighter tint. Whorls 6, the two apical smooth, glossy, the 

 rest convex, separated by a deep suture, slowly increasing, sculptured 

 with numerous arcuate radiating thread-like lirae ; last whorl ob- 

 tusely angled or shouldered above the middle, and much more 

 finely lirate beneath than above. Aperture obliquely lunate. Peri- 

 stome thin, very slightly reflexed near the umbilicus. 



Greatest diameter 7g millim., smallest 6i, height 4. 



This species very closely resembles II. coma of Gray, but is more 

 narrowly umbilicated, just a trifle more finely lirate, and lias the 

 body-whorl roundly angulated above the middle. 



Sandwich Islands. 



Only the three following species, two Melanias from Honolulu and 

 a Neritina from Hilo on the east coast of Hawaii, were brought 

 home by the expedition. 



1. Neritina cariosa, Gray. 



The shell figured in Wood's Index Test. Suppl. pi. 8. f. 9, as 

 Nerita cariosa is undoubtedly the species from the Sandwich Island?, 

 and not the Mauritian N. mauritii as supposed by Von Martens 

 (Conch. -Cab. ed. 2, Monogr. Neritina, p. 276). The type is still 

 preserved in the British Museum, having formed part of the late Dr. 

 Gray's private collection, which he a short time before his death 

 presented to the Museum. It has the apex remarkably eroded, and 

 but very little white speckling on the outer surface. Very little 

 importance need be attached to the fact of its locality being given as 

 Africa, for the next species but one, N. smithii, a well-known Indian 

 form, is also stated to inhabit that locality. 



2. Melania mauiensis, Lea. 



This species has now been recorded from three of these islands 

 (Maui, Molakai, and Oahu), and in all probability it occurs on Hawaii, 

 the largest of the group. 



3. Melania newcombii, Lea 1 



I am rather uncertain whether the series of little shells from this 

 locality really belong to this species. They are very slender, consist 

 of about five moderately convex whorls (the apex being invariably 

 broken away), which are coated with an earthy deposit, beneatli 

 which is a light olive-greenish epidermis. They are sculptured with 

 a few spiral striae, which become more or less obsolete upon the two 

 last whorls except around the base of the last, where they are usually 

 maintained. The length is 1 6" millim., widtli 5, and the aperture is 5 

 long and 3 wide. 



