new Species of Pleurotomide. 215 
Pleurotoma (Mangilia) decora. 
Pleurotoma costata (Gray), Reeve, Conch. Icon. f. 298. 
Hab. St. Vincent, West Indies. 
The name costata was used by Pennant many years ago 
for a species belonging to the section Mangilia, long before 
the publication of Reeve’s description in the ‘ Conchologia 
Teonica.’ 
Pleurotoma (Mangilia) opalina. 
Testa ovato-fusiformis, pallide purpurascenti-alba; anfractus 8, 
primi 2 leves, convexi, vitrei, tertius tenuiter costatus, ceteri 
superne leviter concavi, medio subangulati, infra angulum con- 
vexiusculi, costis circiter 12 (in anfr. ultimo fere basi productis) 
instructi, liris spiralibus 6-7 (quarum due circa medium ceteris 
paulo crassiores sunt) cincti; anfractus ultimus liris cir- 
citer 24 ornatus; apertura angusta, longit. totius 4 adequans ; 
labrum extra valde incrassatum, medio macula parva fusca nota- 
tum, superne leviter sinuatum, intus superne obsolete unidenta- 
tum ; columella callo tenui superne labro juncto induta ; canalis 
brevis, angustus. 
Long. 8 mill., diam. 3. 
Hab. ——? 
The entire surface is finely reticulated by the wavy lines of 
growth and spiral striations ; but these are not visible under 
an ordinary lens. . 
Pleurotoma (Mangilia) trizonata. 
Testa ovata, alba, dilute fusco zonata (in anfr. superioribus zonis 
duabus, altera superne prope suturam, altera ad basim, in anfr. 
ultimo tribus); anfr. 8, primi 2 leves vitrei, cateri convexius- 
culi, superne aliquanto constricti, costis rotundis superne ante 
suturam evanidis (in anfr. ultimo 9 basi continuis) instructi, striis 
minutis spiralibus incrementique lineis pulcherrime insculpti ; 
apertura linearis, angusta, longit. totius + equans ; labrum intus 
incrassatum, superne. obsolete unidentatum; columella callo 
minute granuloso induta ; sinus parvus, minime profundus. 
Long. 84 mill., diam. 35. 
Hab. Sibonga, Zebu Island, 30 fms. (H. Cuming). 
The sculpture of the third and fourth whorls from the apex 
is of a different character from that of the four succeeding. 
The ribs are thinner and more numerous; and spiral lirations 
take the place of the fine striation of the latter. 
Pleurotoma (Mangilia) rufocincta. 
Testa ovato-fusiformis, turrita, pallide flava, cirea medium anfr. 
ultimi zona rufo-purpurea, superne prope suturam rufo tincta, et 
