UNIVALVE MOLLUSCA. 459 
The head of the animal is furnished with two horns or tentacles, 
‘with ocelli upon their external side, the mouth elongated in the form 
of a proboscis. The foot is large and round, and furnished with a 
horny operculum. 
Among the species with long slender tube, covered with spines, 
one of the most notable is AZurex ‘enuispina (Fig. 294), which is a 
native of the Indian Ocean and the Moluccas. 
Fig. 292.—Harpaarticularis Fig. 293.—Murex haustellum _ Fig. 294.— Murex tenuispina 
(Lamarck). (Linnzus), (Lamarck). 
Among the strong-tubed species with long canal and no spines, from 
the same regions, is Murex haustellum (Fig. 293). 
Among the short-tubed species, furnished with foliaceous and 
jagged fringes, is Murex scorpio (Fig. 295). 
One more typical species may be noted, namely,. Murex erinaceus 
(Fig. 296), which is found on all the coasts of Europe, and especially 
in the Bntish Channel. Other species worthy of notice are found in 
the Mediterranean and Adriatic, some of them, according to Cuvier 
and de Blainville, species which furnished the true Tyrian purple of 
the ancients ; but our space prevents us from dwelling on them. 
