TAB. XXVII. 



Fig. 



1. Pleurotoma fusiformis. No. 153, p. 228. 



a. Back view. 



b. Front view. 



2. Pleurotoma sulculosa. No. 154, jc*. 229- 



a. Back view, young shell, from Potters' Bar. 



b. Back view, shell of mid-growth, from ditto. 



c. Back view, adult shell, from Highgate. 



3. Pleurotoma acuminata. No. 155,^. 230. 



a. Back view, adult shell, from Highgate. 



b. Front view, adult shell, from ditto. 



c. Front view, adult shell, from Hornsey, smooth variety. 



d. Front view, adult shell, from Clarendon Hill. 



4. Pleurotoma microdonta. No. 158, jy. 236. 



Side view, adult shell, from High cliff. 



5. Pleurotoma desmia. No. 161, p. 240. 



Front view, shell nearly adult. 



6. Pleurotoma pyrulata. No. 156, p. 232. 



a. Back view, adult shell. 



b. Side view, ditto. 



7. Pleurotoma attenuata. No. 159, jo. 232. 



a. Side view, shell nearly adult. 



b. Side view, adult shell. 



c. Back view, shell of mid-growth. 



8. Pleurotoma conica. No. 160, p. 239- 



a. Back view, adult shell. 



9. Pleurotoma cymsea. No. 142,^. 215. 



a. Back view, young shell, from Colwell Bay. 



10. Pleurotoma terebralis, var. No. 157. p. 233. 



a. Back view, shell magnified (var. ditropis), from Hampstead. 



b. Back view, shell magnified (var. gyrata), from Hornsey. 



c. Back view, shell natural size (var. ggrata), from Shenfield. 



d. Back view, shell magnified (var. gyrata), from Southampton. 



e. Back view, shell magnified {var.pulckerrima), from Highgate. 



/. Back view, shell natural size (var. revolida), from Clarendon Hill. 



g. Back view, shell magnified (var. pulcherrimd), from ditto. 



h. Back view, shell natural size (var. Pagoda), from ditto. 



i. Front view, shell natural size (var. concinna), from Potters' Bar. 



k. Front view, shell magnified (var. concinna), from Highgate. 



note. — The lines indicate the size of the specimens. 



