70 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



PLATE 8 



Figs. 1-7 diagrams of telescoping in vertical region of mysticete skulls. 



Fig. I. Eubalccna. No. 2^077, U- S. Nat. Mus. 



Fig. 2. Cetotherium (from Van Beneden and Gervais). 



Fig. 3. Rhachianectes (from R. C. Andrews). 



Fig. 4. Balwnoptera, young (from Eschricht). 



Fig. 5. Balccnoptera sp. No. 236680, U. S. Nat. Mus. 



Fig. 6. Balicnoptcra sp. No. 16039, U. S. Nat. Mus. 



Fig. 7. Sibbaldus. No. 49757, U. S. Nat. Mus. 



Fig. 8. Spalax sp. (from Mehely). To show development of occipital shield 



and reduction of exposed area of parietals in a burrowing rodent. 

 Fig. 9. Balccna (from Eschricht). Longitudinal section of skull in frontal 



region to show presence of occipital, frontal and nasal at one 



vertical plane. 



