24 MOLLUSCA. TRACHELIPODA. 



SECTION I. ZOOPHAGOUS TRACHELIPODA. 



FAMILY I. INVOLUTA. 



Shell without canal, but having the base of its aperture notch- 

 ed or effuse, and its spiral turns broad, compressed, and rol- 

 led up in such a manner that the last almost entirely covers 

 the rest. 



This family contains six genera : Conus, Olivet,, Ancillaria, Terebellum, Cyprcea^ 

 Ovula. 



Gen. ]. CONUS, Lin. 



Shell turbinate, or in the form of a reversed cone, convoluted ; 

 aperture longitudinal, narrow, not toothed, effuse at its base. 



The genus Conus is the most beautiful, the most extensive, and the most interest- 

 ing of the spiral and unilocular univalves. It contains shells, the most remark- 

 able for the regularity of their form, and the variety and elegance of their colours. 

 They are highly prized by collectors. The animals respire only by branchias, and 

 have the head furnished with two tentacula, which bear the eyes near their summit. 

 They have a narrow mantle, and a tube above the head, by which the water gains 

 admittance to the respiratory organ. They are all marine. 



* Shell coronate, or furnished with protuberances round the spire. 



C. marmoreus, Lin. Shell oblong turbinate, black; with subtri- 

 gonal white spots; spire obtuse, crowned with tubercles, the turns 

 concave. 3 inches long. Inhabits the seas of Asia Lister, 

 pi. 787, fig- 39. 



C. imperialis, Lin. Shell oblong turbinate, whitish ; with green- 

 ish bands, and transverse articulated lines of white and brown ; 

 spire obtuse, depressed, crowned with pretty large tubercles. 3 

 inches long. Inhabits the seas of Asia. Klein, Ost. pi. 4, fig. 84. 



C. Cedo-nulli, Lin. Shell turbinate, coronate, with separated or 

 confluent white spots, and transverse articulated lines of brown 

 and white ; spire concave, acute. 2 inches long. Inhabits the 

 seas of South America and the West Indies. D'Argenv. App. 

 pi. 1. fig. H. 

 There are several varieties of this beautiful shell, some of which are extremely 



rare and valuable. One variety which formerly belonged to M. Lyonnet was valued 



at three hundred guineas. 



C. Hebrceus,lu\i\. Shell turbinate, coronate, white, with several trans- 

 verse series of squarish or oblong black spots ; the spire convex, 

 obtuse. 1J inch long. Inhabits the seas of Asia, Africa, and 

 America Bonan. 3, fig. 122. 



** Shell not coronate. 



C. millepunctatus, Lin. Shell turbinate, white, with numerous trans- 

 verse series of brown or black spots ; spire obtuse ; the turns sub- 

 canaliculate. 4J inches long. Seas of Asia Lam. vii. 461. 



C. litteratus, Lin. Shell turbinate, white, with numerous trans- 

 verse series of brown and black spots ; three orange zones ; spire 

 flat, truncate ; whorls canaliculate. 3^ inches long. Inhabits the 

 seas of Asia. Bonan. 3, pi. 365. 



C. generalis, Lin. Shell oblong, turbinate, brown or orange ; black 



