174 



NOTES ON TAPES. 



By the Rev. CANON HORSLEY. 



(Read before the Society, March 8, 1905). 



Convalescing at Cette during February, and enjoying the sun and 

 the seabreezes on the miles of sandy shore the Mediterranean here 

 presents, I devoted myself largely to the observation of the marine 

 shells of the sea on the one side of the town and those of the Etang 

 (or lagoon) of enormous size, which stretches between Cette and the 

 real mainland on the other. As the great Canal du Midi pours into 

 this the shells herein have a somewhat estuarine character. I know 

 little of marine shells — I might be described, perhaps, as a mere Heli- 

 cologist — but as of all the terrestrial species H. explariata was the only 

 one not entirely hybernating (though H. pisana would soon emerge) 

 I collected the numerous bivalves and less common univalves of these 

 shallow and rockless expanses of water. Between sixty and seventy 

 species I distinguished in spite of my ignorance, and in spite of the ab- 

 sence of any landward wind that would cast fresh shells upon the shore. 

 In some places, especially on the Etang, shell beaches were formed, and 

 a tube simply thrust into them came up full of the prevalent forms. 

 Scores of fishermen, perhaps hundreds, seem to spend all their time in 

 gathering shellfish, especially oysters, Tapes (called in French "moules") 

 and mussels. The oysters of the sea command a higher price than those 

 of the lagoon. All three are very largely eaten raw, and provided as 

 hors d'oeuvres at the beginning of every ddjeuner in a restaurant or 

 hotel. There are here apparently three species of Tapes — T. decussatus, 

 the large, strongly decussated, form, not so common, and not varying 

 so remarkably in colour and marking, as T aiit-eus. I think there is 

 an intermediate form, T. intertnediiis, to judge by the names in the 

 local (and scandalously unarranged) collection in the Marine Labora- 

 tory, established here by the neighbouring University of Montpellier. 

 This may, however, be but a larger form of T aureus. I have separated 

 those that seem to be of this kind. T. aureus gains its specific name 

 from the bright yellow colouring of the interior of the shell, but this 

 colouring is by no means constant, in fact, it is hardly found in the 

 majority of specimens. It does not seem to disappear when dead 

 shells bleach upon the shore. The very varying markings and tints ot 

 the shells appear in the youngest shells in the same way that the pig- 

 ment-glands that form the bands of H. nemoralis begin to operate 

 directly the shell has left the egg. With regard to the colouration of 

 T. aureus., or of its periostracum, I noticed (i) that the tints lost some 

 tone or depth when the animal was extracted. Some that when alive 

 were of a slaty blue, or pinkish lilac colour, were less attractive when 



