Mr. E. Duprey on Jersey Littoral Shells. 185 



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XXVI. — Shells of the Littoral Zone in Jersey. — Supplement 



By E. Duprey. 



The littoral zone of the south coast of Jersey is the rich field 

 that has yielded the following additional harvest of shells. 

 The greater number are of small size, and have been ob- 

 tained by sifting seaweeds about low-water mark and in rock- 

 pools. ^ Many have been found in fine shelly gravel, a few- 

 others in a peculiar and, I believe, hitherto unnoticed habitat. 

 Conchologists are well aware that the ordinary and common 

 abode of a great variety of marine animals is under stones. 

 But if such stones as lie flat upon the ground are often turned 

 over and examined, those which are buried more or less deeply 

 are overlooked. At first sight their appearance is not pro- 

 mising, especially when the upper surface alone is visible ; 

 yet I would invite attention to them when in the lower part 

 of the littoral zone. 



It may be found hard work to turn over stones buried 8 or 

 10 inches or more, and weighing upwards of a hundredweight ; 

 but a welcome reward will often follow. Surprising as it may 

 seem, living under the ponderous mass delicate and rare little 

 mollusks come into view, such as Argiope capsula, Chiton 

 scabridus and C. cancellatusy Rissoa striatula and R. lactea, 

 Adeorbis subcarinatus, and Area lactea f this last rarely. I 

 have also noticed an Ascidian, a Serpula, a Spirorbis, and a 

 few sponges, one of which forms a thin brown velvety pile. 

 These underground marine mollusks are mostly gregarious ; 

 and four or five species may be found living together. It is 

 also worthy of notice that their shells are all devoid of colour, 

 being whitish or stained with a ferruginous tint. Sometimes 

 (as in the case of Rissoa striatula and R, lactea) the stones are 

 imbedded in a firm clayey sand ; but generally the ground 

 consists largely of stones and pebbles, intermixed with sand 

 and gravel and a little mud. Such a soil is easily permeable 

 to water, but not shifting to any extent, as proved by the 

 growth of algse and Zostera. A glance at one of the " good " 

 stones when turned over is enough to show that only a portion 

 of the under surface was in contact with the underlying soil. 

 The other or " fertile " portion must have overlain a space 

 filled with clear water, and formed, as it were, the roof of a 

 miniature underground cavern. The force of the current 

 above during the ebb and flood of the tide is no doubt suffi- 

 cient to induce a slight flow of the water permeating the loose 







See the Ann. & Mag. Nat Hist, for October 187& 



Ann. & Mag. N. Hist. Ser. 5. Vol. xi. 13 



