120 NOTES ON THE HELICIDJS, BY C. HEDLEY. 



NOTES ON THE HELICIDiE ; 



By C. HEDLBT. 



Helix rainbirdi, Cox. Animal 55 m.m. long, rounded in front, 

 and rapidly tapering behind to an acute point. Tentacles sub- 

 cylindrical 18 m.m, long, tapering from swollen contiguous bases, 

 mantle bright blood-red, anterior portion of body and muzzle black, 

 tentacles chesnut, tail chesnut with central brown stripe. Sides 

 ornamented with reticulating grooves running downwards and 

 forwards from three central furrows along the neck, which termin- 

 ate in a minute pit at the bases of the tentacles. Tail sub-keeled 

 with slight central groove whence branch to the margin of the foot 

 an obscure network of minute furrows. 



The jaw is high, arcuate, ends truncated, denticulated on both 

 margins by six stout ribs as broad as their interstices. 



The lingual ribbon has the central tooth with base of attach- 

 ment longer than wide, posterior lateral angles expanded, anterior 

 margin broadly reflected, tapering slowly to a stout, almost square- 

 headed cusp whose cutting edge surpasses the posterior margin. 

 In the first six laterals, the outer expanded angle becomes wing- 

 shaped, the inner being suppressed ; these six teeth attain the 

 largest size and bear a more ovate cusp than that of the rachidian ; 

 further from the centre the base of attachment becomes more 

 symmetrical, presenting an almost square appearance in the 18th 

 series. Denticles gradually appear in the remote laterals, and the 

 extre.ne marginals become trifid. 



On dissecting the genitalia, the penis-sac at the end of its 

 straight cylindrical portion is seen to perform a spiral revolution, at 

 the apex of which the short vas deferens takes its departure. The 



