new Gastropoda from the Persian Gulf, &e. d21 
Without a knowledge of the anatomy of these small species 
of Tectibranchs it is often mere guesswork assigning them 
to generic positions. ‘This species, however, seems best 
located in Cylichna, in our opinion. It is a delicate, mode- 
rate-sized species, of a peculiar hepatic tint, this suggesting 
the proposed specific name. 
Retusa omanensis, sp.n. (Pl. XXIII. fig. 19.) 
R. testa parva, cylindrica, albo-lactea, subhyalina, tenui, supra 
truncatulo, apice fere immerso ; anfractibus 3, supra excavatulis, 
marginibus apud suturas acutis, prominulis, superficie omni spira- 
liter sub lente delicatissime striata; apertura postice latiore, 
oblonga, antice angusta, labro recto, ad basim rotundata; colu- 
mella obscure uniplicata, margine paullum incrassato. 
Alt. 4, diam. 1°75 mm. 
Hab. Gulf of Oman, lat. 24° 58’ N., long. 56° 54’ E., 
156 fathoms. 
A most delicate and minute species, of the same character 
as Uiriculus complanatus, Watson, from Papua (‘ Challenger’ 
Rep. xv. p. 650, pl. xlviii. fig. 9), but that species is longi- 
tudinally striate. We follow Pilsbry (Man. Conch. xv. p. 203) 
in the nomenclature, and would refer to his reasons for the 
substitution of Retusa, Brown, 1827, for the more familiar 
Utriculus, Brown (in parte), 1844, non Schumacher, 1817. 
Atys flavovirens, sp.n. (Pl. XXIII. fig. 20.) 
A. testa ovata, in medio tumida, utrinque producta, tenuissima, 
subdiaphana, pallide flavo-virente, apud medium levi, nitida, 
antice, simul ac postice, spiraliter paucistriata, apice plicato, 
labro tenui, paullum effuso; apertura anguste lunari; columella 
uniplicata. 
Alt. 7, diam. 3 mm. (sp. maj.). 
Hab. Gulf of Oman, Maskat, 15 fathoms. 
Allied to A. tortuosa, A. Ad., from the Philippines and 
Torres Straits ; the shell is smaller, and more green than 
yellow-tinged. Mouth narrower, the anterior as well as the 
posterior strie being fewer and less pronounced. Many 
examples. 
Mathilda carystia*, sp. n. 
M. testa gracili, fusiformi, eleganter attenuata, brunnea, brunneo- 
nigra, vel, imprimis, castanea ; anfractibus 12-13, quorum apicalis 
heterostrophus, pervitreus, globularis, caeteris apud suturas im- 
pressis, binis preecipuis levibus carinis preeditis, sex vel septem 
* «dapvoy kapvarcov, from the chestnut colour. 
Ann. & Mag. N. Hist. Ser. 7. Vol. xii. 21 
