Part 20

2. POTAMIS. The same, fresh water. Fig. 377.

3. NERINEA. The same, with internal folds. Fig. 374.

4. TRIPHORA. Anterior and posterior canals closed so as to present three openings. Fig. 375, 376.

5. TELESCOPIUM. Pyramidal, trochiform. Fig. 378.

6. PLEUROTOMA. A slit on the upper part of the outer lip; including Clavatula. Fig. 379, 381.

7. TURBINELLA. Three horizontal folds on the columella. Fig. 382, 383.

8. SPIRILLUS. Spire papillary; one fold on the columella. Fig. 384.

9. CANCELLARIA. Three folds, and internal costæ. Fig. 385.

10. FASCIOLARIA. Oblique folds, the lowest the largest. Fig. 386.

11. FUSUS. Fusiform; no folds on the columella. Fig. 387.

12. PYRULA. Pear-shaped. Fig. 388 to 390.

13. STRUTHIOLARIA. Outer lip thickened; sinuated. Fig. 391.

14. RANELLA. Two rows of varices; a canal at each extremity of the aperture. Fig. 393, 394.

15. MUREX. Three or more rows of varices; only one distinct canal. Fig. 395, 396.

16. TYPHIS. A tubular perforation between each varix. Fig. 397.

17. TRITON. Varices not in rows. Fig. 398 to 401.

CANCELLARIA. Auct. (From Cancellatus, cross-barred, like window frames or net work.) Fam. Canalifera, Lam. Entomostomata, Bl.--Descr. Oval, thick, cancellated; spire generally short, pointed; aperture sub-ovate, emarginated anteriorly, pointed at the posterior extremity; outer lip marked within by transverse ridges; inner lip spread over part of the body whorl, terminating in a straight, thick, obtuse columella, with several strong oblique folds. Hab. Indian Ocean, Coast of Africa, America, and West Indies. Fossils found in London Clay and Calc-grossier of Paris. Differing from Turbinellus in form and in the transversely ribbed inside of the outer lip. Fig. 315. C. reticulata.--Obs. The latest enumeration of the species of this genus is contained in a catalogue published by Mr. G. B. Sowerby, senior, accompanying the author's figures of the new species, amounting to 38, in parts 9 to 13 of the Conchological Illustrations. The greater part of these new species were brought to this country by Mr. Cuming.

CANCELLATED. (From Cancellatus, cross-barred.) Applied generally to any shells which are marked by ridges crossing each other as Cancellaria, fig. 385.

CANCILLA. Sw. A sub-genus of Mitræ, described as having "the whorls crossed by transverse linear ribs; inner canal wanting, plates very oblique; form slender; outer lip thin." Ex. M. Isabella, M. sulcata.

CANCRIS. Montf. CREPIDULINA, Bl. A genus of microscopic Foraminifera.

CANOPUS. Montf. A genus of microscopic Foraminifera.

CANTHAPLEURA. Guild. A genus composed of those species of Chiton, which have the mantle rough, with moveable spines, prickles, or hairs. Ex. C. spinosus, fig. 227.

CANTHARIDUS. Montf. TROCHUS IRIS, Auct. and analogous species. Elenchus, Humph.

CANTHARUS. Montf. A genus of microscopic Foraminifera.

CANTHIDOMUS. Sw. A sub-genus of Melanopsis, thus described: "spire generally short; whorls coronated with spines, or marked with longitudinal ribs; base obtuse. C. costata, Sow. Gen. f. 3." Melanopsis costata, plates, fig. 315.

CANTHORBIS. Sw. A sub-genus of the sub-family Trochinæ, Sw. Described as being "nearly disc-shaped: spire but slightly raised; the margin of the body-whorl flattened, and serrated with flat spines; inner lip united to the outer; pillar and aperture as in the last. (Tubicanthus.) C. imperialis. Mart. 173. f. 1714." This sub-genus appears to include those species of which De Montfort's genera Imperator and Calcar are formed.

CANTHROPES. Montf. Described as resembling a Nautilus, with the whorls increasing so gradually, that the dorsal edge of the aperture advances but little beyond the last whorl. This genus is not mentioned by Blainville or Lamarck.

CAPITULUM. Klein. POLLICIPES Mitellus, Lam. fig. 37*.