1S79.] * ANATOMY OF HY.ENA CROCUTA. 87 



placed higher in the laryngeal box than the posterior. They are (as 

 is the case also in Proteles) separateJ from the base of the epiglottis 

 in front and from the arytseno-epiglottidean folds of mucous mem- 

 brane of each side by a deep sinus, the mucous membrane of 

 which is smooth and glistening. The space enclosed by the false cords 

 is oval in form and of such width that the true vocal cords can be 

 readily seen from above. The latter are much stronger and thicker 

 than the false cords, and approach more closely to the middle line of 

 the larynx ; between them is the rima glottidis, which is triangular 

 in form. Judging from Mayer's figure of the larynx of H. striata, 

 that of H. crocuta closely resembles it, differing, however, in the 

 possession of well-marked false vocal cords, which, according to the 

 author named, are absent in the former species. At the same lime 

 it is to be observed that Meckel' does not deny the presence of both 

 false and true vocal cords in the larynx of H. striata. Taken as a 

 whole, the larynx of //. crocuta, like that of Proteles, as pointed out 

 by Prof. Flower, presents a greater resemblance to that organ in the 

 Felidse than in the Canidse, differing from the former, however, in the 

 oblique position and diminished prominence of the false vocal cords, 

 and from both in the greater projection anteriorly of the thyroid 

 cartilage, as well as in the presence of a sinus which separates the 

 false cords from the base of the epiglottis and arytseno-epiglottidean 

 folds of mucous membrane. 



Thyroid gland. — Is very small and of an elongated-oval form. It 

 lies under cover of the sterno-thyroid muscle, and extends on each 

 side from the middle of the cricoid cartilage down to the sixth 

 tracheal ring. The two hrdves are not connected by an isthmus. 



Trachea. — Is 11 inches in length. It possesses 49 cartilaginous 

 rings (according to Meckel" .53); individual variation may account 

 for this difference. The rings vary very much in breadth. In the 

 trachea of H. striata, according to Meckel, there are 45, according 

 to Reimann^ and Wolff^ there are but 36 ; in Proteles Mr. Flower 

 counted 36. 



Lungs. — The right lung is divided into 6 lobes, the left into 3. 

 In the right lung there are two horizontal fissures, the lower of 

 which indicates the separation between a basal lobe (which forms 

 about one half of the lung) and the rest of the organ. The upper or 

 apical half is divided into four lobes through the intersection of the 

 upper horizontal by a vertical fissure. Of these, the lower and pos- 

 terior lobe is almost square, and clearly separated from that above 

 and below it, whilst the two anterior lobes are scarcely so well 

 defined by reason of their coalescence towards the root of the organ. 

 TJie sixth is the so-called azygos lobe, and lies between the upper 

 and lower halves of the lung. The left lung is divided into an upper, 

 a middle, and a lower lobe by means of two horizontal fissures, the 

 inferior of which separates the lower from the upper half of the lung, 

 whilst the upper divides the latter into two parts. Of these, 

 the upper is the larger. On the outer surface of this lobe is a 



^ Op. cif. vol. X. p. 6.S.5. " Op. cit. vol. x. p. 48.5. 



3 Pe Hyaena, Berol. 1811, p. 16. * De org. vocie, Eerol. 1812, p. 10, 



