BOYCOTT AND JACKSON: ANATOMY OF HELICELLA " HERIPENSIS." 167 



As has been already mentioned, the external surface of the body was 

 on the whole a good deal darker in the ^^ /leripensis" ; the internal 

 pigmentation seemed, however, to be independent of this since the 

 usual arrangement was found in two specimens of " heripensis " with 

 pale grey bodies and in one caperata with a body almost black. 

 In two specimens of caperata there was much more diffuse pigmenta- 

 tion of the inner wall of the pulmonary sac and in the connective 

 tissue elsewhere than was present in other specimens of caperata or 

 "■ heripensis'''' \ in both of these, however, the neck of the dart sac and 

 the duct of the spermatheca were quite free from pigment. 



The significance of these differences was finally tested experiment- 

 ally. A number of each form was taken by one of us, the bodies 

 extracted and labelled A or B according as they were one or other 

 form as judged by the shell. Tiie bodies so labelled were then given 

 to another person, ignorant of what shells they had come from and 

 indeed of the question under examination, who rearranged them under 

 distinguishing numbers. Under these numbers they were then 

 passed on to the other of us who made a diagnosis oi'''' heripensis''^ or 

 caperata by anatomical results. Finally the conchological and 

 and anatomical diagnoses were compared and found to correspond in 

 every case. 



The conclusion which we should like to draw from this enquiry is 

 that the anatomy of the forms known as " heripensis " and caperata is 

 worth further investigation. The present material is particularly 

 suitable for direct comparison because both forms were collected at 

 the same time in the same habitat and did not differ very widely in 

 size. But whether there are any anatomical differences which could 

 be added to the differences in shape and sculpture of the shell to 

 substantiate the claim that ^^ heripensis " is a "good species " cannot, 

 of course, be settled from a single instance. We would, therefore, 

 suggest that conchologists who are in a position to obtain the necessary 

 material should further investigate themselves the points which we 

 have raised or should send us specimens for examination. The snails 

 are best sent alive, soon after collection ; we shall be glad to return 

 the shells if desired. 



Note.-— It is perhaps as well to point out here that although we 

 have used the specific name of heripensis Mab. for the form differing 

 from caperata by reason of its finer sculpture and excentric umbilicus, 

 it must not be inferred that we consider this to be the correct name of 

 the species in question, as in our opinion the form agrees exactly with 

 H. gigaxii (Charpentier ms.) Pfeiffer, 1850. If this identification 

 proves to be correct the specific name gigaxii has priority. . 



