64 



MEANS OF CONCEALMENT 



CHAP. 



Modiola adriafica, M. barbata, and sometimes M. modiolus con- 

 ceal themselves in a similar way. G-astrochaena frequently 

 encloses itself in a sort of half cocoon of cement-like material. 

 The singular genus Xenophora protects itself from observation 

 b}^ gluing stones, shells, and various debris to the upper side of 

 its whorls (Fig. 25). Sometimes the selection is made with 

 remarkable care ; the Challenger^ for instance, obtained a speci- 

 men which had decorated its body whorl exclusively with long 

 and pointed shells (Fig. 26). 



Fig. 25. — Xenophora {Phorus) 

 conchy Hojjhora Born., con- 

 cealed by the stones which 

 it glues to the upper surface 

 of its shell. (From a British 

 Museum specimen.) 



Fig. 26. — Xenophora {Phoi-us) pallidula Reeve. 

 A mollusc which escapes detection by cover- 

 ing itself with dead shells of other species. 

 (From a Challenger specimen in the British 

 Museum, Xj.) 



The formidable spines with which the shells, e.g. of the 

 Murex family, are furnished must contribute greatly to their 

 protection against fishes, and other predatory animals. Murex 

 tenuispi7ia^ for instance (see chap, ix.), would prove as dangerous 

 a morsel in the mouth of a fish as a hedgehog in that of a dog. 

 Whether the singular tooth in the outer lip of Leucozonia (see 

 chap, xiv.), a feature which is repeated, to a less marked extent, 

 in Monoceros and several of the West Coast muricoids, is devel- 

 oped for defensive purposes, cannot at present be decided. 



The Strombidae possess the power of executing long leaps, 

 which they doubtless employ to escape from their foes. In their 

 case alone this power is combined with singular quickness of 

 vision. On one occasion Mr. Cuming, the celebrated collector, 

 lost a beautiful specimen of Terebellum^ by the animal suddenly 



