754 MR. H. ADAMS ON NEW MOLLUSKS. __ [Dec. 12, 
was dredged by Mr. M‘Andrew off Gibraltar. It is in the finest 
possible condition, and the nucleolar whorls, which are sinistral and 
somewhat planorbular, show that the place of Hg/isia is in the family 
Pyramidellide, and not in Turritellide, in which it has been hitherto 
included. 
AMPHITHALAMUS OBESUS, H. Adams. 
A. testa obesa, dense rufo-cornea, nitida, levi, subdiaphana, mar- 
ginibus spire excurvatis ; verlice nucleoso normali, haud sculpto, 
apice mamillato; anfr. 5, subplanatis, rapide augentibus ; bast 
tumida, haud sculpta; apertura subovali; labro acuto; labio 
(¢. adulte) a pariete separato, thalamum altissimum formante, ad 
marginem recto, ad junctionem labri antice curvato. 
Long. 14, lat. ¢ mill. 
Hab. Lord Hood’s Island (Coll. mea). 
AMPHITHALAMUS PUpOIDEUs, H. Adams. 
A. testa angusta, dense rufo-cornea, nitida, levi, subdiaphana, mar- 
ginibus spire irregularihus ; vertice nucleoso valde mamillato, 
tumente, haud sculpto; anfr. 4, subnlanatis, vie augentibus, ul- 
timo paulum angustiore ; basi prolongata, haud sculpta; apertura 
(¢. adulte) subcirculari, peritremate rufo, continuo; labro vix 
angustato ; labio a pariete parum separato, thalamum lacunatum 
formante, ad junctionem labri antice curvato. 
Long. 13, lat. } mill. 
Hab. Lord Hood’s Island (Coll. mea). 
This species stands on the confines of the genus, and passes 
towards Stenothyra, in shape, however, resembling Hyala. 
HETEROCARDIA DENNISONI, H. Adams. 
H. testa ovata, subcompressa, tenui, equilaterali, hiante, albida, 
transversim inequaliter striata; latere antico rotundato, margine 
superiore paulo incurvato; latere postico arcuatim subtruncato, 
inferne rotundato ; umbonibus parvis, subprominentibus. 
Long. 37, alt. 27, lat. 15 mill. 
Hab. ? (Coll. mea). 
This species, which is the largest of the very rare genus Hetero- 
cardia, is most like H. cumingii, Desh., but is much more oval in 
form, and has tlie umbones central. The specimen described formed 
part of the collection of the late Mr. Dennison, and is the only one I 
have seen. 
Genus Tuyriua, H. Adams. 
Testa equivalvis, subtriangularis, postice subtruncata, vie flexuosa, 
ventricosa, epidermide tenui pallido-fulva induta, superficie val- 
varum decussata. In valva dextra dentes duo cardinules, quorum 
anterior triangularis, bifidus, posterior minor, compressus ; in 
valva sinistra dens cardinalis solitarius, triangularis, bifidus ; 
ligamentum internum, in fovea subcentrali vix declivi positum ; 
dentes laterales nulli. Impressiones musculares satis conspicui, 
posterior rotundata, anterior elongata ; linea pallialis sinuata. 
