236 ON THE CETACEAN GENUS MESOPLODON. [Feb. 28, 



EXPLANATION OF THE PLATES. 

 Plate XII. 



Fig. 1. Upper surface of cranium of Mcsoplodon grayi, Haast, type, \ nat. size. 



1 a & 1 A. Transvei'se sections of the rostrum of the same at a and b respec- 

 tively, nat. size. 



2. Outline transverse section of M. haasti, Flower, after Flovrer, for com- 

 parison with the sections 1 a and 1 b, nat. size. 



Plate XIII. 



Fig. 1. Upper surface of cranium of Mcsoplodon grayi, Haast — the Kaiapoi 

 skull (I), J nat. size. 

 1 a & 16. Transverse sections of the rostrum of the same at a and b respec- 

 tively, nat. size. 



2. Outline transverse section of M. austral is, Flower, after Flower, for 



comparison with the sections 1 a and 1 b, nat. size. 



Plate XIV. 



Fig. 1. Transverse section of rostrum of Zipkius cavirostris. $• 



2a&2b. Transverse sections of the rostrum of a young individual of 

 Mesoplodon grayi, Haast. Cf. fig. 1, page 221. 



3. Outline transverse section of the rostrum of M. grayi, Haast, in the 



R. Coll Surgeons, alter Flower. 

 4 a- & 4 6. Transverse sections of the rostrum of M. grayi, Haast, 5 > ^^ 



Canterbury Mus., Christchurch, N.Z. 

 5. Transverse section of the rostrum of M. grayi, Haast, 2 , in the Otago 



L'niv. Museum, N.Z. 



Fig. I is J nat. size ; figs. 2-5 nat. size. 



Plate XV. 



Figs. 1, 2. Transverse sections of Mesoplodon grayi, Haast — Specimen E in 

 list above, from the Chatham Islands, nat. size. 

 3-5. Transverse sections of M. grayi, Haast— G in the list above, from 

 the Chatham Islands : fig, 4 is the most anterior and 5 the most pos- 

 terior section, and all are of the nat. size. 



ExPLAN.iTiON OP Abbreviations. 



br.g. Basirostral groove. 



butt. Maxillary buttress. 



gib. Gibbosity. 



mr. Mesorostral bone. 



mr.s. „ suture. 



mr.cr. „ crease. 



mx. Maxillary bone. 

 mx.f. „ foramen. 



mx.i. ,, ingrowth. 



meth. Mesethmoid bone. 

 meth.s. Anterior termination of mesethmoid boue. 



pmx. Preuiaxillary boue. 

 pmx.s. „ suture. 



pmx.o. „ ossification. 



pmx.f. „ foramen. 



s.oc. Supraoccipital bone. 



V. Vomer. 

 v.s. Vomerine suture. 

 v.tr, „ trough. 



16 JUN 1898 



