MOLLUSCS. 



337 



A description of the more common species of cones would prove dull reading, and 

 so we merely mention the colors of the two species figured. Conus marmoreus is 

 dark or even black, marked with triangles of white, while U. textile is very variable, 

 the general ground color being golden or orange, on which are laid brOwn reticulating 

 lines and white spots. The cones are favorites with collectors, and rightly so, for they 

 are among the most handsome of shells. Some of the species are very rare. Conus 

 gloriormaris, a white species with orange spots and triangular lines, has been sold for 

 two hundred dollars, while some of the rarer varieties of C. cedo-nuUi (a very variable 

 species) have brought over one hundred dollars. The former comes from the eastern 

 seas, while the latter is West Indian. Of course these prices do not 

 indicate any intrinsic value in the shell, but are merely indices of the 

 comparative rarity, and of the prices which rich collectors are willing 

 to pay for certain noted species. Other species equally rare would 

 not command a small fraction of these prices, merely for the reason 

 that they are not so well known, and dealers have not yet attempted 

 to speculate upon them. 



The Teeebeid^ contains about two hundred species of long, 

 slender, many-whorled shells from the tropical seas. They are readily 

 distinguished from other similar forms by the small aperture with an 

 anterior siphonal notch, and by the absence of true plaits on the 

 columella. The tentacles are short, and the eyes, when present, are 

 near or at the tips. The Terebras are known among the sailors as 

 auger-shells. 



About as little need be said of the Pleueotomid^, 

 in which the shell is spindle-shaped, the aperture pro- 

 longed anteriorly while near the suture there is a notch. 

 An operculum is not always present. Although some 

 five hundred species are known, but little of popular 

 interest can be detailed concerning them. The genus 

 Pleurotoma is represented on our eastern shores by a 

 few small and inconspicuous species usually assigned 

 to the sub-genera Bela and Mangelia, while on the 

 Pacific coast the species are about equally numerous. 

 In the West Indies and at Panama many more forms 

 are found. 



The Cancellaeid^ differ from the other Toxi- 

 glossa in being vegetarians, and they differ further in having the pro- 

 boscis rudimentary. The shells may be recognized by the folds on the 

 "roS^Ci'l^r columella and on the outer lip, and the fact that the shell is almost 

 '"""'■ always marked off into squares by transverse ribs and revolving lines 



which gives rise to the name of the principal genus Cancellaria. The species live 

 in comparatively shallow water, though they are but very rarely found above low-water 

 mark. In the northern Atlantic the family is represented by a small white shell 

 about half an inch in length, known as Admete viridula. No specimens are known 

 to have come from south of Cape Cod. 



Fia. 424.— Tcrefcra 

 oculata. 



VOL. I.— 22 



