690 



MR. G. E. DOBSON ON THE 



[June 7, 



In E. cotnptus the structure of all the above-described parts is 

 similar — with this exception only, that the tendons of the mylo-hyoid 

 and hyo-glossus muscles pass forwards together below the epihyal 

 process. No male specimens of JJ. pusillus are available for exami- 

 nation ; but, judging from the anatomy of the female, it agrees in 

 all respects with that of E. comptus. In E. monstrosus, which 

 differs from all the other species in the absence of the shoulder- 

 pouches, there are no posterior air-sacs ; but the anterior sacs are 

 well developed, and separated internally below, not by a thin parti- 



Fig. 5. 



a.r 



Vertical and longitudinal section througli the centre of the larynx of 

 EiMmojjJiorns franqucti (enlarged). 



e, epiglottis; h.c, hyo-epiglottideus muscle ; h.h, basihyal bone; th.c, thyroid 

 cartilage ; /. v. c, false vocal cord ; v, ventricle leading anteriorly into 

 the long sacculus laryngis, extending almost as far as tlie base of the 

 epiglottis, and posteriorly continued backwards behind v. c, the true 

 vocal cord ; ar, arytenoid cartilage ; s, apex of Santorinian cartilage ; 

 c, crescentic fibro-cartilaginous cushion extending forwards from the 

 arytenoid cartilage ; cr, cricoid cartilage. 



tion as in the above-named species, but by an intermediate inferior 

 sac communicating with the pharynx by an aperture between the 

 mylo-hyoid tendons. 



In E. macrocqjhalus, gamhianus, labiatus, and minor the thyro- 

 byals are very long, having their broad extremities bent inwards 

 above so as to nearly meet in the middle line above the laryngeal 

 opening ; the basihyal (fig. 6, b.hy) is much produced forwards, ter- 

 minating in a straight thin edge, to the outer sides of which the 

 very short ceratohyals are attached by ligament only, and have a 



