4 ON THE CETACEAN LARYNX. 
This case in Globiocephalus illustrates sufficiently in itself all the main points 
of importance which the Delphinoid larynx presents us with. I figure certain 
additional specimens to illustrate or corroborate minor points. 
The youngest fcetus in our collection is that of a Narwhal, whose total length 
was 8 centimetres. 
Boe 
Fig. 7. Larynx or rorran Nanwest(<3). BELuca 
ac.pc., anterior and posterior thyroid cornu. 
The arytenoids are here comparatively large, oval cartilages, set somewhat wide 
apart, above and a little to the side of the ericoid cartilage. The supra-arytenoids 
are very small and delicate: they rise upwards to a pointed apex overtopped by the 
epiglottis, from a broad base attached to the arytenoids: the anterior or inferior 
process running forwards over the arytenoids appears to be as yet undeveloped. 
The cricoid is peculiar: its anterior processes are rather short and stout, and 
beneath them the inferior angles of the cartilages, with which the posterior thyroid 
cornua articulate, project to a shorter distance laterally ; so that the cricoid looks like 
a broad posterior plate from which two pairs of lateral processes project instead of 
one. The thyroid has the anterior and posterior cornua well developed: the former 
are reflexed, forming a deep notch which answers to an imperfect thyroid foramen. 
The epiglottis is already solid and cartilaginous, and is very firmly attached at its 
base to the anterior border of the thyroid. 
In an older but still young fcetus of Beluga, about 20 cm. in length, the 
cricoid has attained nearly to the conformation of the adult. Its posterior surface is 
broad and massive, with a median longitudinal ridge: anteriorly (or ventrally) it is 
incomplete, as it remains in the adult; and all trace of the lateral extension of its 
posterior angles seen in the earlier stage has disappeared. The arytenoids are as 
distinct and separate as in the former case: they are still oval nodules of cartilage, 
lying somewhat closer together and with their long axes more nearly coincident, 
Paps ae eines | eh \ eaprarercs s,Ar Ep: 
—--Ar 
Timee 
beer ni mee == 
yj 
Figs. 8 and 9. Larynx or rorraL Besvex NARWHAL. 
From behind and from the left side (x 3). 
