( 33 ) 



DIVISION XVI. CRICOSTOMATA. 



1. Turbo. (1) Lam. 

 Round or oval : thick. 



GENERA. 



Mouth completed by 

 the penultimate whorl. 



a. Meleager, Montf. Umbilicate. PI. 9, fig. 3. 



b. Turbo, Montf. Not umbilicate. PI. 12, 6g. 15. 



2. Turritella. (2) Lam. 



Spire elongated like an Mouth completed by 

 obelisk ; thin : operculum the penultimate whorl, 

 horny or cartilaginous. PI. 

 9,%. 12. PI. 12,fig. 17. 



3. Vermicula.ru. Adan- 

 son. 



Whorls not touching, 

 irregularly curved. PI. 9, 



fig. 



Ditto. 



4. Delphinula. (3) Lam. 



Thick ; rolled almost in Mouth entirely formed 



the same plane. PI. 9. fig. by the last whorl. 

 16. 



Ditto ; but margined. 



5- Scalaria (4) Lam. 



Turreted, with pro- 

 jecting sharp longitudinal 

 ribs. PI. 9, fig. 6. 



6. Aciona. (5) Leach. 

 Wendletrap. 



Ditto, but whorls dis- Mouth entire and mar- 

 tinet and distant ; no co- gined. 

 lumella. PI. 9, fig. 5, 



Marine. 



V. Animal, p. 65. 



Marine. 



V. Animal, p. 65. 



Marine. 



V. Animal, p. 65. 



Marine. 



V Animal, p. 65. 



Marine. 



V. Animal, p. 



65. 



Marine. 



Animal unknown. 



(1) Foss. in the Crag Marl; atPresles; Grignon. No fossil species of this genus 

 has been discovered in the Fresh Water Formations ; the little shell of the ponds 

 of Havre and Magentonc have been erroneously referred to it. 



(2) Foss. in the London Clay; Crag Marl ; at Grignon, Chaumont. 



(3) Foss. Grignon, Courtagnon. 



(4) Foss. in the London Clay ; Crag Marl ; at Grignon^ Prestes. 



(5) " The museum of Mr. Bullock contains the largest known specimen of the 

 Aciona Scalaris, which was purchased at a sale for twenty-seven pounds; but it 

 is now estimated at worth more than double that sum."— Leach's Zoological Mis' 

 cctlany, vol. 2. 1815. 



