TROCHUS.—P tate XV. 
Very closely allied to 7. sacedlum, but of a more sharply 
conical form, more strongly tubercled. 
Species 91. (Fig. a, 6, Mus. Cuming.) 
TrocHus TRIcaTENATUS. Troch. testé excavato-umbilt- 
cata, subobtusé conicd, solidd, interdum fulvescente- 
albd, roseo-flammatd, interdum virescente, cinereo- 
olivaceo flammatd ; anfractibus superne et inferne 
angusté tricatenatis, medio validé triseriatim  gra- 
natis, margine basali rotundato ; basi convewxinsculd, 
confertim seriatim granatd, sparsim maculatd. 
THREE-CHAINED TrocHvs. Shell excavately um- 
bilicated, rather obtusely conical, solid, sometimes 
THE 
fulvous-white, flamed with rose, sometimes greenish 
flamed with ash-olive ; whorls narrowly three-chained 
at the upper and lower parts, encircled round the 
middle with three rows of strong grains, basal margin 
rounded; base rather convex, closely serially grained, 
sparsely spotted. 
2 
Hab. 
The whorls of this species are encircled with three rows 
of bold wart-like grains, bound above and below by a 
narrow transversely stretched chain. 
Species 92. (Mus. Cuming.) 
TrocHus PALLIDULUS. Troch. 
umbilicatd, subobeso-conicd, solidd, fulvescente-albi, 
testa wodicé vacavato- 
immaculala ; anfractibus valide papillari-granatis, 
granis juxta suturas confertioribus, subplicatis ; basi 
conveaiusculd, seriatim granatd. 
THe paLeE Trocuus. Shell moderately excavately um- 
bilicated, rather stoutly conical, solid, fulvous-white, 
unspotted ; whorls strongly papillarly grained, grains 
next the sutures closer, subplicate ; base rather con- 
vex, serially grained. 
Polydonta pallidula, Adams, Pro. Zool. Soe. 1851, p. 155. 
Hab. ? 
Resembling in general aspect the obese grained forms 
of Littorina. 
Species 93. (Mus. Cuming.) 
The shell here figured is a characteristic type of Dr. 
Philippi’s 7. sacedlum, of which we have given a smaller 
coral-red variety in the preceding Plate. 
Species 94. (Mus. Cuming.) 
Trocuts mptaLiicus. Zroch. testd subunguste wunbilicaté, 
acute conicd, enco-virente, purpureo sparsim punctald ; 
anfractibus undique granatis, granis medianis regular i- 
bus, superioribus oblique plicatis, inferioribus parvis, 
confertis ; basi plano-concavd, seriatim yranatd. 
THE METALLIC TROCHUS. 
bilicated, sharply conical, metallic-green, sparsely 
Sheil rather narrowly um- 
dotted with purple; whorls grained throughout, 
middle grains regular, upper grains obliquely pli- 
cated, lower grains small, close-set ; base flatly con- 
cave, serially grained. 
9 
Hab. 
The colour of this species is a peculiar verdigris-green, 
imparting a metallic hue to the shell. The purple colour 
is sprinkled in small promiscuous blotches. 
