PLATE XXVII. 



Fig. 



1. Turrilites costatus ; young, from the Grey Chalk of Ventnor, Isle of Wight; in 

 my possession, p. 66. 



2a, b. Turrilites costatus ; adult, with the mouth completely formed ; from the Grey 

 Chalk of Ventnor, Isle of Wight ; in my possession, p. 66. 

 2a, side view. 

 2d, view of the base, with the perfect mouth. 



3 and 4. Turrilites costatus ; two small specimens which have already formed the 

 produced mouth; from the Grey Chalk of Ventnor, Isle of Wight; in my 

 possession, p. 66. 



5. Turrilites costatus; young, from the Grey Chalk of Ventnor, Isle of Wight; in 

 my possession, p. 66. 



6 and 7. Turrilites bifrons ? .D'Orb. ; from the Lower Chalk, Ventnor, p. 67. 



8. Turrilites Wiestii ; from the Grey Chalk of Ventnor, Isle of Wight ; in my posses- 

 sion, p. 67. 



9a, b. Turrilites Wiestii ; young, from the Chalk with siliceous grains, Charclstock, 

 Somersetshire; in the collection of Mr. John Morris, p. 67. 

 9a, side view. 

 9b, base of a whorl. 



10. Turrilites Bergeri ? var. ; from the Chloritic Marl of Bonchurch, Isle of Wight. 



(Mr. Saxby.) 



11. Turrilites Puzosianus, D' Orb. var. ; from the Chloritic Marl of Bonchurch, p. 68. 



12. Turrilites costatus, var. ; from the Lower Chalk of Ventnor, Isle of Wight. 



13. Turrilites tuberculatus, var. ; from the Lower Chalk of Ventnor. 



These two figures (12, 13) are doubtfully referred to the above species, and 

 may hereafter prove to be distinct : the specimens are only fragments, and in 

 an imperfect state of preservation. 



14a, b. Turrilites Wiestii, var. ; from the Lower Chalk of Ventnor. 



15. Turrilites costatus, var. T. triplicates, J. Sow. ; Lower Chalk, Sussex; from the 



original in the British Museum, p. 66. 



16. Septum of T. contains, p. 66. 



17. Septum of T. Wiestii, p. 67. 



