ANATOMY OF MEGAPTERA LONGIMANA. 



145 



border of the rib near the wing of the sternum ; 6, &', anterior angle 

 of right and left rib, less developed on the left ; c, c', posterior angle of 

 the ribs. The left rib is seen to be shorter than the right. The notch 

 between the two angles here is seen to be shallower 011 the left rib. 



Sternum. The dotted part on the cervical process is where it has 

 been covered by cartilage. The sub-cartilaginous end of the wings is 

 not seen when viewed from before. The figure shows the more hori- 

 zontal direction of the posterior border of the right wing, in adapta- 

 tion to the greater projection of the anterior angle of the right rib. 

 On the left side, the hollow between the wing and the cervical process 

 is seen to be more filled up than on the right side, but the difference 

 on the two sides is not so great as that between the wing and the 

 posterior process. The radiating lines indicate the direction of the 

 vascular grooves and foramina, converging to the thicker part of the 

 bone. 



Compare with this figure the figure of the corresponding parts in 

 B. musculus, in this Journal, vol. vi., 1871, fig. 4, showing the liga- 

 ments of the two costo-sternal articulations, &c. 



PART IV. 

 THE SKULL. 



Page 



1. Table I., Measurements, . 146 



2. Length and Proportions, . 148 



3. Occipital Region, . . 149 



4. Temporal Fossa and Pass- 



age, .... 151 



5. The Bones at ditto., . . 153 



6. Malar Bone, . . .156 



7. The Orbit, . . . .156 



8. Transverse Frontal Fossa, . 157 



9. Length and Proportions of 



Cranium, . . .158 



10. Nasal Bones, . . .158 



11. Posterior Nares, . .160 



12. Anterior Naris, . . .161 



Page 



13. Nasal Cavity, . . .162 



14. Ethmo-Turbinals, . .163 



15. Prenasal Space, . . .164 



16. Maxillary and Premaxil- 



lary, . . . .165 



17. Ant -Orbital Process of Max- 



illary, . . . .166 



18. The Beak, . . . .166 



19. Foramina on Facial Surface 



of Maxillary, . . .168 



20. Beak on Palatal Aspect, . 169 



21. Vascular Grooves on Palatal 



Surface, . . . .170 



22. Cranial Cavity, . . .171 



The following table of measurements, besides showing the 

 size and proportions of the various parts of the skull of this 

 Megaptera, will enable these to be compared with the corre- 

 sponding parts of B. musculus. The measurements to which 

 an * are prefixed are those given in the same order by Professor 

 Flower (Proc. ZooL Soc., 1864, p. 411) of several skulls of B. 

 musculus, with which the sizes in the second column of my table 



may be compared. Some of the measurements given in the 



N 



