412 THE ZOOLOGIST. 



aid of Fisheries District Committee, to institute inquiries and 

 research in furtherance of such steps as might lead to the mitiga- 

 tion of the mischief threatening a prominent and important 

 commercial industry of the two counties. 



There are other matters concerning "Limpets" {Crepidula 

 fornicata), e. g. their habits, relations to associate organisms, 

 wherefore deleterious to British stock — though presumed to be 

 less troublesome in America — uses to be put to, &c., which we 

 reserve for a future occasion. Meantime, the present accompany- 

 ing illustrations may help to convey an idea of how things stand 

 with the Oyster's parasite messmate. 



Appeiidix. — Since the foregoing was in type, and on my 

 exhibiting specimens of the " Slipper Limpet " at the Linnean 

 Society Meeting (Nov. 2nd), Prof. Dendy called my attention to 

 a paper bearing on the subject by a pupil of his : " On the 

 Occurrence of Protandric Hermaphroditism in the Mollusc 

 Crepidula fornicata," by J. H. Orton, Proc. Roy. Soc. B. vol. 81, 

 (1909). Unfortunately this had escaped my attention, else 

 should have been referred to in the body of the present paper, 

 especially as based on animals collected on Essex shores. 



At the same time, Orton's researches and deductions, like 

 Conklin's (l. c), dwell more particularly on the biological or 

 physiological phases. Indeed, with some few exceptions, they 

 only indirectly pertain to the everyday wants and working of 

 the local fisheries, therefore irrelevant to the object of our 

 paper. Withal, we here give in extract Orton's otherwise inte- 

 resting investigations, which seem to be a continuation of 

 Conklin's on the sexuality of the genus. He first draws atten- 

 tion to and gives a diagram of seven Crepididce, in arched form 

 on an Oyster-shell (similar to our fig. 6 in Plate VIL). The 

 three lower "Limpets" are females, above which an imperfect 

 male, and then three fully developed males. He agrees with 

 Conklin as to chains once formed are thereafter permanent 

 fixtures, whereas the youngsters are motile. Five diagrams 

 follow, illustrative of sexual anatomy ; one of these shown 

 as hermaphrodite by possessing both penis and uterus. He 



