LITTORINA. | 587 
L. conspersa in two characters, viz., the more globose form and the more elevated 
ridges; but among the Mazatlan specimens in the Berlin Museum there are several 
which combine the slender form of conspersa with the strong ridges of puncticulata. 
13. Littorina aspera. (Tab. XLIII. figg. 15, 16.) 
Littorina aspera, Philippi, P. Z.S. 1845, p. 1891; Abbild. neuer Conch. ii. p- 200, t. 4. fig. 13’; 
Menke, Zeitschr. f. Malak. 1847, p. 178°, and 1850, p.163*; C. B. Adams, Ann. Lyc. Nat. 
Hist. N. York, v. p. 894 (1852) *; Carpenter, Catal. Mazatlan Shells, p. 348°; Kiister, in 
Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Litorina, p. 61, t. 8. figg. 2,37; Mérch, 
Malak. Blatt. vii. p. 69 (1860-61) °; Troschel, Gebiss d. Schnecken, i. p. 187, t. 11. fig. 4 
(radula) °; Tryon, Manual of Conch ix. p. 249, t. 45. fig. 87 (copied from Reeve) *°. 
Littorina apicina, Menke, Zeitschr. f. Malak. 1850, p. 164 (young state) ™. 
Litorina irrorata (Say), Reeve, Conch. Icon. x., Litorina, t. 11. fig. 56” (nec L. irrorata, Say, 
from the east coast of North America). 
Near ZL. lineata, but with the spiral ridges stronger and somewhat rough; the last whorl usually differing 
from the upper ones in having the spiral ridges more prominent and somewhat knobbed; the basal keel 
more distinct in younger specimens, but sometimes almost disappearing in very old ones (fig. 16). 
Hab. N.W. Mexico: Mazatlan, common (Melchers? 48, Reigen®); West Coast of 
Mexico (Uhde, in Mus. Berol.); Mexico, without nearer indication of locality 
(Hegewisch ! ). 
SaLvaDor : Conchagua (Cuming !2); La Libertad (Krause, 1881, in Mus. Berol.). 
W. Costa Rica: Punta Arenas, on stones (@rsted®); Gulf of Nicoya (C. Hoffmann, 
in Mus. Berol.). 
S. Pavama: Taboga Island and Panama, on ledges and large fragments of rock at 
or above high-water mark (C. B. Adams°). 
Our figures are taken from a very old specimen, 19 millim. in length, in Paetel’s 
collection (fig. 15), and from a young one from Nicoya (fig. 16). 
Carpenter ¢ is quite right, I think, in doubting the occurrence of this species so far 
north as Sitka, whence it has been recorded by Philippi1?. Won Middendorff 
[Malacologia Rossica, p. 66] has seen no specimen from thence in the Petersburg 
Museum, but mentions it only on the authority of Philippi. 
The other species of Littorina mentioned by C. B. Adams in his valuable ‘ Catalogue 
of Panama Shells’ live in somewhat deeper water, between half-tide and high-water 
levels (L. atrata), or have been found only as dead shells in sand, and they belong to 
the genus Fossarus, according to Carpenter (Moli. W. N. Am. p. 188). : 
Littorina aberrans, Philippi (P.Z.S. 1845, p. 142; Abbild. neuer Conch. ii. p. 11, 
t. 6. fig. 9; Reeve, Conch. Icon. x., Litorina, t. 12. fig. 59), from Panama, founded on 
a single specimen in Cuming’s collection, probably does not belong to his genus also ; 
Carpenter (Moll. N.W. Am. p. 60), however, says that it is a tall variety aie conspersa, 
