JOURNAL OF CONCHOLOGY. 267 



THE DARTS OF BRITISH HELICID^. 

 By CHARLES ASHFORD. 



PART VII. (concluding). 



The seventeen species which have now been described 

 comprise all the British dart-bearers at present known. Of the 

 remaining species of both genera — Zonites and Helix — all have 

 received a certain amount of examination from various mala- 

 cologists, and the organisation of a large majority has been 

 thoroughly ascertained. Nevertheless, it would be satisfactory 

 if some of the minuter kinds underwent, at the hands of a skilful 

 manipulator, a more rigorous and a final scrutiny. A few 

 examples of Helix lamellata and H. aculeata, obligingly sent me 

 from the North of Scotland, by Mr. W. Baillie, of Brora, yielded 

 no positive evidence, but in these cases the entire bodies were 

 dissolved without previous dissection. 



To sum up, we have in the British Isles — with two darts — 

 If. ericetorum, H. rufescens, H. concinna, and H. hispida ; with 

 one dart, Zonites nitidus, Z. excavatus, Helix pomatia, H. aspersa, 

 H. nemoralis, H. hortensis, H. arbustorum, H fusca, H. Fisana, 

 H. virgata, H caperata, H. pulchella, and H lapicida/, or, 

 arranging in accordance with the form of dart-sac, we have — 

 with two bilobed sacs, H. rufescens^ H. concinna, H hispida ; 

 with two simple sacs, H. ericetorum ; with one bilobed sac, 

 Z. excavatus, H. fusca ; with one simple sac, Z. nitidus, H. 

 pomatia, H. aspersa, H. nemoralis, H. hortensis, H. arbustorum, 

 H. Pisana, H virgata, H caperata, H pulchella, H. lapicida. 



We find then that, omitting the two Zonites, the ratio of 

 dart-bearing Helices to all the species of that genus in this 

 country is 15 to 25, or 60 per cent. In 1853, Adolf Schmidt 

 reported that he had examined iip to that date 77 species of 

 Helix, chiefly European, with a few from N. Africa and Syria, 

 and had found 51 furnished with darts. This is about 66 per 

 cent. The per-centage for France alone, as nearly as can be 



