570 MR. T.?GOODEY ON THE SKELETAL' [Mar. 15, 



28. Ridewood. — " Caudal Diplospondyly in Sharks." Journ. 



Linn, Soc, Zool. vol. xxvii., 1899. 



29. Sedgwick. —A Student's Text-Book of Zoology. Vol. ii. 



London, 1905. 



30. Stewart. — " On the Membranous Labyrinth of certain 



Sharks." Journ. Linn. Soc, Zool. vol. xxix., 1906. 



31. Woodland. — " The Anatomy of Gentrophorus calceus." Proc. 



Zool. Soc. 1907. 



XII. EXPLANATION OP THE PLATES. 



Plate XLII. 



Fig. 1. Side view of skull, jaws depressed showing ethmo-palatine process and its 

 articular facet. Slightly less than half natural size. 



2. Median vertical longitudinal section of cranium and anterior part of vertebral 

 column. Slightly reduced. 



3. Jaw-joint seen from inside, widely open. X \. 



4. Postero-lateral view of first and second visceral arches and their connecting 



ligaments. X i. 



5. Internal view of jaw-joint showing relation of quadrato-hyoid ligament. 



X|. 



Plate XLIII. 



Fig. 6. Ventral view of branchial arches, showing vestigial seventh branchial arch. 

 Xt 



7. Membranous labyrinth seen from the inside. X 2. 



8. Membranous labyrinth seen from the outside. X 2. 



9. Vertical longitudinal section of anterior end of vertebral column, showing 



calcified cyclospondylic centra. Slightly reduced. 

 10. Vert, longit. section of anterior end of vertebral column of large female 

 specimen, showing cyclospondylic centra. Slightly reduced. 



Plate XLIV. 



Fig. 11. Portion of vertebral column from trunk region with ribs attached. Nat. size. 



12. Transitional region from mono- to diplospondylic condition of vertebra; ; 



the numbers n. 70, etc. denote neuromeres; note especially n. 72. Nat. 

 size. 



13. Portion of vertebral column from main caudal region, n. 89 to n. 91; note 



calcified bands. Nat. size. 



14. Vert, longit. section of fig. 13 ; note the calcified incipient centra. Nat. 



size. 



15. Portion of vertebral column from main caudal region of large female specimen, 



the ridged extensions of the arcualia round the notochord are well shown. 

 Nat. size. 



16. Vert, longit. section of fig. 15, calcified cyclospondylic centra of two sizes 



are well shown. Nat. size. 



Plate XLV. 



Fig. 17. Terminal caudal region, heterospondylic region. Nat. size. 



18. Left pectoral fin ; note fused proximal segments of radials attached to 



mesopterygium, also two postaxial radials. Nat. size. 



19. Dorsal view of right half of pelvic girdle and fin of female. X i. 



Plate XLVI. 



Fig. 20. Dorsal view of right half of pelvic girdle and mixipterygium, showing 

 musculature. X i- 



21. Ventral view of fig. 20, X §. 



22. Dorsal view of skeleton of right mixipterygium; note modified radial 0, 



and intercalary cartilage, b. 1. X i. 



