ANIMAL TO ITS SHELL IN SOME FOSSIL CEPHALOPODA. Ill 



Plate 18. 



TurrUites tuberculatus, Bosc (p. 83). 

 Fig. 1. Lateral aspect, two of the upper wliorls exhibiting the siphuncle {si), and tlic body-cliamber 

 showing the muscular attachment, x ^. 

 2. Dorsal aspect of body-chamber of same, showing the muscular attachment. X \. 



TurrUites Mantelli, Sharpe (p. 83). 

 Fig. 3. Lateral aspect of fragment, the lower whorl of which exhibits a portion of the boundary of the 

 muscular attachment. x |. 



TurrUites {Heteroceras) polyplocus, Roemer (p. 84) . 

 Fig. 4. Lateral aspect of terminal portion. X |. 



Oxynoticeras ? sp. (p. 85) . 

 Fig. 5. Left lateral aspect of part of an example showing the muscular scar and the annulus. x 5. 

 0. Right lateral aspect of same, x f . 



Amaltheus spinatus, Bruguiere, sp. (p. 86). 



Fig. 7. Left lateral aspect of imperfect specimen, exhibiting on the inner portion of the whorl (opposite 

 the arrow) the boundary of the muscular scar. 



Cardioceras excavutum, J. Sowerby, sp. (pp. 75 & 86). 

 Fig. 8. Left lateral aspect, showing the muscular scar and the annulus. x h. 



Cardioceras aff. excavuto, J. Sowerby, sp. (p. 80). 



Fig. 9. Left lateral aspect, exhibiting the ar.tcrior boundary of the muscular scar on the inner portion 

 of the whorl opposite the aiTow, and a linguiform impression on the middle of the lateral 

 area. 

 10. Dorsal aspect of posterior portion of the body-chamber of the same, showing near the base the 

 course of the anterior boundary of the muscular scar on the dorsal area of the whorl. 



Tissotia EwahU, v. Buch, sp. (p. 90). 



Fig. 11. Left lateral aspect, showing close to the umbilicus (opposite the arrow) one of the muscular 

 scars, and, passing from it towaids the peripheiy, a portion of the anterior boundary of 

 the annulus. x f . 



Plate 19. 



Cardioceras excaratnm, J. Sowerby, sp. (p. 86). 



Fig. ] . Right lateral aspect, x §. 



2. Sagittal section of the natural internal cast of the body-chamber of the same specimen, showing 

 anterior boundary of muscular scar on dorsal portion of whorl. X f . 



Cardioceras sp. (p. 89). 



Fig. 3. Left lateral aspect, showing anterior boundary of scar and of annulus. x 'j. 



4. Ventral view of the same, exhibiting the impression on the central portion of that area. 

 SECOND SERIES — ZOOLOGY. VOL. YII. 10 



