MOLLUSCA. 
129 
Genus Rissoa. — (Page 10.) 
56. Rissoa tbistriata. 
Rissoa trisiriata, Thompson, Ann. Nat. Hist., V, pi. 2, f. 10; 
Macgillivray, Moll. Ab., p. 151. 
Shell conical, ovate, thin, glossy, subdiaphanous ; body ven- 
tricose, somewhat longer than the spire ; spire consisting of 
four moderately convex volutions, defined by a rather shallow 
sutural line, which is accompanied by a narrow spiral line, with 
also two smaller lines and three striae, terminating in a rather 
obtuse apex ; aperture large, of a short oval form, and occupy- 
ing about half the length of the body ; outer lip thin, destitute 
of any thickening behind ; colour yellowish-white, the body 
with three bands of squarish red-coloured spots. Length a 
twelfth of an inch ; diameter two-thirds of its length. 
Found by Mr. Alexander Murry, in shell sand, from the Bay 
of Cruden. 
57. Rissoa gracilis. 
Rissoa gracilis, Macgillivray, Moll. Ab., p. 152. 
Shell thin, pellucid, glossy, turreted, subcylindrical ; consist- 
ing of six moderately convex volutions, defined by a deep 
sutural line; aperture obliquely ovate, a little contracted above, 
occupying about a fourth of the entire length of the shell; outer 
lip complete, a little thickened externally ; inner lip narrowly 
reflected on the columella, with a slight cavity behind ; body 
ferruginous around the aperture ; spire cream-white. Length 
somewhat more than the twelfth of an inch ; diameter a fourth 
of its length. 
In form it resembles Rissoa striata, but is more elongated, 
and is nearly allied to Rissoa ruber, which, however, is less 
attenuated with a rounded aperture. 
Found by Miss Anne Macgillivray, in shell sand, on the 
beach between the estuaries of the Dee and Don, Aberdeen- 
shire. 
Genus Trochus. — (Page 18.) 
14. Trochus Martini, pi. L VII, f. 11. 
Trochus Martini, Brown, Wernerian Mem., VIII, p. 51, pi. 
1, f. 26. 
Shell conical; consisting of seven flat-sided volutions, well 
defined by the suture, and terminating in an acute apex ; the 
whole covered with five or six tuberculated spiral ridges, which 
can only be distinctly seen by the aid of a strong lens, the 
lower ridge of each volution being more prominent than the 
others ; base imperforate, flat, and a little concave, furnished 
with numerous tuberculate, concentric ridges; whole surface 
citron or flesh-coloured, streaked with nearly equidistant, red- 
dish-brown, irregularly-shaped spots; aperture subquadrate, 
compressed, and nacred within. 
First discovered by Major Martin, of Mayville, Ayrshire ; it 
has since been dredged by Mr. Smith, of Jordan Hill, in the 
Kyles of Bute; by Professor Forbes, off the Isle of Man; and 
near Dublin, by Mr. Alder, of Newcastle ; and is said to have 
been found on the Aberdeenshire coast. 
5. Trochus perfobatus, p. 18, pi. LVH, f. 9, 10. 
Genus Tornatella (Page 21.) 
2. Tornatella pellucida. 
Tornatella pellucida, Macgillivray, Moll. Ab., p. 158. 
2 K 
Shell ovate, very thin, diaphanous, and glossy, conical, some- 
what fusiform ; volutions divided by a well defined sutural line, 
nearly flattened on the sides, and tapering to a sharp apex, 
and are longitudinally striulated, and spirally striated ; body 
nearly twice as broad as the length of the spire, more deeply 
striated at the base and towards the suture, where there are 
two punctulate impressed lines, the basal strise minutely crenu- 
late ; edge of the volutions simply incurved ; aperture oblong, 
narrow, the superior angle being considerably contracted by the 
convexity of the lower volution of the spire ; outer lip 
extremely thin; columella with an obscure plait; colour cream- 
white, with two faint reddish bands on the body. Length 
somewhat more than an eighth of an inch ; diameter more than 
half its length. 
“ It closely resembles a young Tornatella fasdata, but differs 
in having the spire longer and more pointed, in wanting the 
channel in the suture formed by the involution of the spiral 
turns, in having two impressed lines near the posterior margin 
of the turns, and in being differently coloured. The three 
reddish bands, however, are analogous to the reddish spaces 
between the white bands in Tornatella fasdata” 
Found in the Bay of Aberdeen, by Professor Macgillivray. 
3. Tornatella pusilla. 
Tornatella pusilla, Macgillivray, Moll. Ab., p. 158; Voluta 
fusiformis, Turton, Conch. Diet., p. 259. 
Shell very thin, transparent, glossy, ovate, conical, and sub- 
fusiform ; spire with three distinctly divided, slightly convex 
volutions, tapering to an obtuse apex; body about twice as 
broad as the length of the spire, with three spiral, punctulate 
striae, which are strongest below, obsolete and distant on the 
upper two-thirds, crowded towards the suture; aperture oblong, 
narrow, considerably contracted at its upper extremity, by the 
convexity of the lower volutions ; outer lip extremely thin ; 
columella with an inconspicuous, oblique, obtuse plait or nodo- 
sity, terminating the inner lip ; colour cream-white. Length 
one-twelfth of an inch ; breadth half the length. 
“ This species has the spire shorter than Tornatella fasdata 
and Tornatella pelludda. It seems to agree in most respects 
with Turton’s Voluta fusiformis, but differs in being only a 
third of the size, and spirally striate.” 
Genus Jaminia. — (Page 21.) 
10. Jaminia scalaris. 
Odostomia scalaris, Macgillivray, Moll. Ab., p. 154. 
Shell thin, transparent, and glossy, ovately conical; consisting 
of five faintly striated, moderately convex volutions, well defined 
by a canaliculate suture, towards which the superior margin is 
suddenly indexed ; aperture ovate, occupying nearly the whole 
length of the body ; outer lip thin ; columellar lip somewhat 
inflexed, and terminating in a prominent plait on the columella; 
colour cream-white. Length not a twelfth of an inch; breadth 
half its length. 
Macgillivray says “ this species differs from all the others, in 
having the pillar lip inflexed, in wanting the umbilicus, and in 
the subscalar form of the spire.” 
Found by Professor Macgillivray, in shell sand, between the 
estuaries of the Dee and the Don, Aberdeenshire. 
11. Jaminia plicatula. 
Odostomia plicatula, Macgillivray, Moll. Ab., p. 156. 
