SCALID OF THE WEST INDIA ISLANDS. 193 
3. SCALA PRINCIPALIS, Pallas. 
T. obtecte perforata, ovato-turrita, tenuiuscula, candida, nitidula, sub lente obsoletissime irregu- 
lanter spiraliter striata; anfr. x disjuncta, costis xiv regularibus acutis in anfr. ult.; apertura 
oblique ovalis, labio rectiusculo. 
Long. 36 mm.; diam. 16 mm.; alt. aperture: 10 mm. 
Turbo principalis, Pallas, Spic. x. 1774, p. 32. 
ae “  Naturg. merckwiird. Thiere, x. 1778, p. 51, t. 3, f. 3, 6. 
Angarius scalaris seu var. rarissima, Meuschen Mus. Gevers. 1787, p. 260, n. 203. 
Die seltene enge geribbte Wendeltreppe, Martini, Berlin, Samml. Bd. Vili, .p...28; 
tab. tit. 
Turbo principalis, Chem. iv. p. 273, f. 1128, 29. 
Schréter Journal, i. p. 451. 
Hab. Tortola, spm. unicum (A. H. Riise). 
Scalaria principalis, Sowb., Thes. fig. 75, p. 88, n. 23, from Xipixapi, is different. 
Scala ducalis, Morch. 
Scala costulata, Kien. Spec. Gen. differs chiefly in having the ribs more 
numerous and lower. 
I am not aware that this species is found in any collection but that of Mr. 
Riise, now in Copenhagen. 
4, ScaLta swirti, Mérch, n. sp., Pl. 29, fig. 3. 
T.. acuminato-ovata, vix perforata, alba, polita, lineis aciculatis, spiralibus, obsoletissimis; anfr 
disjuncti, convexi vii—viii, sutura rimata; costee foliacez in anfr. ult. xii, pagina antica obso- 
letissime rugoso-granulosa; apertura ovata, abbreviata, antice effusa, labio subtorto. 
Long. 14 mm.; diam. 9 mm.; alt. aperture 5 mm. 
Hab. St. Thomas (R. Swift), spm. unicum. 
“Scalaria bulbulus, Sowb.,” Coll. Swift. 
Scala obtusa, Sowb., is the species nearest allied. The aperture is effuse, like 
that of Melania; the ribs of the last whorl touch the front side of the correspond- 
ing ribs of the preceding whorl. 
5. SCALA NovEMcosTATA, Mérch, n. sp. 
1. abbreviato-turrita, imperforata, alba, nitida, tenuiuscula; anfr. disjuncti, convexi, rima angus- 
tissima ; costa compress, acute, altissimee, continue, in anfr. ult. ix. Apertura suborbicu- 
laris, obsolete coarctata. 
Long. 9 mm.; diam. 44 mm.; alt. aperture 2 mm. 
Hab. St. Thomas (Riise), spm. unicum. 
Scala hexagona, Sowb., and epecially Scala foliacea, Sowb., from the Crag 
formation, are nearly allied to this species. 
49 
