LITTORIXA.— Plate I. 



This species may be readily distinguished from all varie- 

 ties of the preceding by its more pyramidal forju, smaller, 

 prickly sculpture, and more concave growth at the suture. 



Species 3. (Mus. Cuming.) 



LiTTOBiNA tectum-Pebsicum. LM. testd obluiue conku, 

 crassa, hnperforatd, laded, Jitsco iiiictd ei Uneata, 

 tramversim striata, et tuberculatd, tuberculin rudiius, 

 promiruiitibns, declivibus, pins minus irreijularibm, 

 colmnelld basi cremdatd. 



The Pbusian-koof Littorina. Shell obliquely conical, 

 thick, imperforated, cream-coloured, stained and li- 

 neated with brown, transversely striated and tnber- 

 cled, tubercles rude, prominent, slanting, more or 

 less irregular, columella slightly notched at the base. 



Turbo tectum-Persicum, Linnneus, Syst. Nat. p. 123i. 

 Monodonta tectum-Persicum, Lamarck. 

 Littorina tectum-Persicum, Deshayes. 



Hah. ? 



Intermediate in its characters, between L. bvlla/a and 



pagodus, and subject apparently to limited variation. 



Species 4. (Mus. Cuming.) 



Littorina pagodus. Litt. testd oblique conicd, actitd, 

 crassd, solidd, imperforatd, fuHcescente-lacied, fusco 

 tinctd et Uneata, anfractibus rugoso-striatis, et com- 

 presse uodulatis, superne declivibus, rude subpUcatis, 

 anfractu ultimo conspicue bittcberculato. 



The pagoda Littorina. Shell obliquely conical, sharp, 

 thick, solid, imperforated, brownish cream-colour, 

 stained and lineated with brown, whorls roughly 

 striated and compressly noduled, slanting round the 

 upper part, rudely subplicated, last whorl conspicu- 

 ously bitubercled. 



Turbo pagodus, Linnaeus, Syst. Nat. p. 1234. 

 Trochus pagodus, Chemnitz. 

 Monodonta pagodus, Lamarck. 

 Littorina pagodus, Deshayes. 

 Tectarius pagodus, Guerin. 

 This well-known species is chiefly remarkable for its 



uniformly large size and more angular sharp growth, the 



entire svirface being more or less plicately striated and tu- 



bercled, the tubercles on the last whorl being developed 



in a prominent double row. 



