SCHULTE, SEI WHALE. 



sulcus. The remainder of the respiratory passage, the naso-pharyngeal duct, is a smooth-walled 

 tubular cavity in which the transverse diameter somewhat exceeds the dorso- ventral. 



The olfactory region communicates with the respiratory passage by a narrow slit-like ori- 

 fice between the broad septum nasi mesad and the crista semicircularis laterad. On the removal 

 of the septum, the crista semicircularis is seen as a sharp falciform margin at the rostral limit 

 of the olfactory region. The dorsal cornu extends to the cribiform plate; the ventral cornu 

 is directed ventrad and caudad, becoming continuous with the maxillo-turbinal which forms the 

 ventral limit of the olfactory region. Lateral to the crista and maxillo-turbinal is a deep narrow 

 depression, the undivided recessus lateralis inferior. The dorso-lateral limit of this recess is 

 formed by the "Sammelleiste," (de Burlet), a ridge of cartilage covered by mucous membrane 

 extending from the crista semicircularis to the lamina transversalis posterior, which forms the 

 caudal limit of the communication between the olfactory region and the respiratory passage. 

 The space above the " Sammelleiste " is divided by the vertical ridge of the first ethmo-turbinal 

 into a caudal recessus posterior and a rostral depression, the recessus lateralis superior. This, 

 as its name implies, is a laterally directed diverticulum of the olfactory region; its fundus, how- 

 ever, is prolonged caudad into a deep recess on the lateral aspect of the first ethmo-turbinal. 

 In its depth are visible two diminutive oblique fronto-turbinal ridges. Of these the second 

 is considerably the smaller and is wholly concealed in median view by the first ethmo-turbinal. 



The recessus posterior or ethmo-turbinal region is smaller than the recessus lateralis. Its 

 rounded fundus occupies the cupula posterior of the nasal capsule. Its orifice is contracted 

 and bounded rostrad by the first ethmo-turbinal, ventrad by the lamina terminalis, dorsad by 

 the cribiform plate, caudad by the free edge of the mesal wall of the cupula posterior. Its 

 lateral wall shows the presence of a well developed third ethmo-turbinal, between which and the 

 first of the series a rudimentary second can be detected. 



Larynx. The larynx conforms so closely to the descriptions of previous writers that it 

 here requires but passing notice. The elongated epiglottis rises high into the pharynx, its 

 enlarged extremity lying above the level of the velum. Rostrad it is connected to the hyoid 

 by a prominent hyo-epiglottic fold of mucous membrane (Turner). On its caudal surface I 

 could find no trace of a Czermak's cushion such as Turner describes. This surface is deeply 

 grooved axially and the lips of the groove are elevated to high triangular folds, which passing 

 lateral to the free rostral margins of the arytenoids, diminish in height and are attached to their 

 lateral surfaces. The arytenoids are high and broad, but very thin and leaf-like. Their dorsal 

 margins are united in about half their extent, the ventral free and boldly curving. The free 

 margins were closely approximated in this foetus, but not adherent and fitted in between the 

 high ary-epiglottic folds described above. There were no vocal cords. The muscles and the 

 cricoid cartilage I did not examine. 



Thyroid cartilage. The thyroid cartilage consists of two symmetrical halves which have 

 not yet fused in the median line, but are closely united by a narrow plate of connective tissue. 

 In general shape it resembles Carte and MacAlister's ' figure much more closely than Turner's, 2 

 but departs from both considerably. The lateral margin is distinctly concavo-convex and serves 

 to give attachment to the inferior constrictor. Its length is 17 mm. The mesal margin, 6.5 

 mm. in length, was for rather more than half of this distance united with its fellow. Caudad 



1 Carte and MacAlister, op. cit., pi. v, fig. 5. 

 Turner, op. rit., pi. viii, fig. 36. 



