26 ' LITTORINIDiE. 



It has evidently no fear of man or fish, being fortunately 

 unconscious that the conchologist and the blenny are 

 its natural enemies. Its heart, however, beats fast in 

 confinement, giving about 60 pulsations per minute. 

 Clark informs us that ^' the branchial plume consists of 

 15-18 minute vessels attached under and to the mantle 

 and back of the neck ; " and according to Mr. Alder the 

 teeth are arranged in 40 or 50 rows. The spawn-capsules 

 are semicircular, yellowish-brown, and sometimes depo- 

 sited on the shells of other individuals. Specimens from 

 the Hebrides and Shetland are much larger than usual, 

 but of a paler hue. The one noticed and figured in the 

 ' British Mollusca ^ as i?. Sarsii is an extraordinarily fine 

 example of the variety interrupta, and not Loven^s 

 species of that name ; it is a quarter of an inch long. 

 Mediterranean specimens are very inferior in size to 

 those of our coasts. Mr. Williams Hockin has noticed 

 that now and then the ribs are slightly furrowed down 

 the middle. This species may always be known from 

 any of its allies by a character which Forbes and Hanley 

 pointed out, viz. the falciform streak outside the mouth. 

 To give all the old sjmonyms (including those of 

 Adams) would be unnecessary. The modern ones are 

 Cingida alba, Fleming, R. pulchella, Forbes, R. tristriata, 

 Macgillivray, R. fuscata and R. discrepans, Brown, R. 

 obscura and R. simplex, Philippi, R. Matoniana, Recluz, 

 Sabancea paucicostata and Persephona Scotica, Lcacli, 

 and R. cerasina, Brusina. Perhaps R. lineolata and /?. 

 marginata of Michaud may be added to the list. 



13. R. iNcoNSPi'cuA*, Alder. 



7i. viconspicua, Aid. in Ann. & Mag. N. H. xiii. p. 32:3. pi. riii. f. G, 7 : 

 F. & H. iii. p. 113, pi. Ixxvi. f. 7, a and Ixxxii. f. o, 6. 



Body white, with blotches of yellow : it is also marked leng'th- 



* Xot remarkable. 



