24 



carboniferous striata. They are world-wide in their distribution, 

 and are found at depths from a few to 3000 fathoms. The British 

 Museum has lately acquired a Pecten which was dredged in the 

 Antarctic Ocean, in Victoria Land, by the Newnes expedition in 

 ten fathoms of water. 



The British Pectcii operatlaris is a beautiful shell, nearly round 

 and very variable in colour, as you will see by the specimens ex- 

 hibited. It is found in 15 to 25 fathoms. Pecten varius<A%o, as the 

 name would indicate, is very variable, and is found on all our coasts. 

 F. tigriuus is a small, beautifully marked species ; but the smallest 

 British Pecten is P. similis, which is very small indeed and very 

 fragile. The specimens shown are from Loch Fynne ; they are not 

 immature as one would suppose from their appearance, but adult 

 and never get any bigger. Pectens are generally hermaphrodite, 

 but sometimes the sexes are separate. One species, Pecten jacobceus, 

 from the Mediterranean, we are told, was worn in the hat as a badge 

 by pilgrims who had been to the Holy Land. 



In foreign Pectens we find all the characteristics of the English 

 in an exaggerated degree, whether it is size, colour, sculpture, or 

 variableness. Some of the tropical species are perfectly fascinating 

 in their beauty and colouring ; notably I would call your attention to 

 Pecten g/al>er from the Hebrides and P. senator/its from Amboyna. 



Woodward tells us that the secretion of colour by the mantle 

 depends greatly on the action of light. Shallow-water shells are, as 

 a class, warmer and brighter coloured than those from deep water. 

 The usual shape of the valves is for the lower one to be hollowed 

 out and the upper valve flat or nearly so ; in Pecten sinensis from 

 China this is exaggerated, as you will see. The colour of the valves 

 usually differs very much ; notice P. japonicum from Japan — one side 

 is quite white and the other a warm brown, exactly the colour of 

 the sand on which it is found. The valves are often unequal ; an 

 exaggeration of this may be seen in Pecten yessoensis from Japan. 

 At first sight it would appear that the valves were not pairs, but on 

 comparison with several specimens of this species at the British 

 Museum I find the form is very constant. Pecten magellanicum from 

 the Straits of Magellan is a shell not often met with ; notice the 

 strength of the valves and the absence of colour, characteristic of all 

 shells from that stormy region. I would also point out a series of 

 Pecten Icetus from the Island of Hiro Shima, Japan, that land of 

 curious things ; there are seven specimens, all the same species of 

 this beautiful shell, ranging in colour from pure white to a rich dark 

 brown. I call your attention to it, as it is a rare shell. Another 

 beautiful thing is Pecten pallium from the East Indies ; you will 

 notice in this species the valves are both alike in form and 

 coloration. 



All Pectens are more or less beautiful, and you can well under- 

 stand that they have always been highly prized by conchologists 

 and collectors. There are many questions that one would like to 



