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Show 294 PROF. W. B. BENHAM ON THE [Apr. 2, margin, and after a very short course is inserted into the dorsal edge of the epiglottid cartilage at about the middle third of its extent (figs. 18, 19). 9. The hyo-epiglottid muscle has the usual relations. 10. The thyro-arytenoid is a small muscle arising from the inner surface of the thyroid plate (PI. X X V I I . figs. 18, 19, T.ar.) below the thyro-epiglottid, and is inserted in the outer surface of the enlarged base of the arytenoid cartilage, between the aryteno-epiglottid and the lateral crico-arytenoid muscles. III. NOTE ON THE LARYNX OF ZIPHIUS. In 1887 a brief account of the external features aud some parts of the skeleton and viscera of a species of Ziphius wTas presented to the Society by Professors Parker and Scott (Trans. Zool. Soc. xii. p. 241). In it the larynx is stated to agree with that of Cetacea in general, but no details or figures are given. The late Prof. Parker had the larynx cut into two symmetrical halves, one half of which is amongst the many anatomical specimens accumulated by him in the laboratory of the Otago Museum, and it may be not without interest to add a brief account of it here. It presents features of greater resemblance to the Porpoise and Grampus than to Cogia (PL XXVIII. fig. 26). The thyroid cartilage is continuous across the ventral surface, though this region is thinner than elsewhere. The body of the cartilage is otherwise like that of Cogia, but is stouter; the "bay" between the posterior cornu and the body is wider and deeper; the anterior cornu (which has been cut across) is more distinct. The cricoid, on the other hand, is incomplete ventrally as in several other Odontocetes ; its dorsal and lateral regions are much stouter than tbe corresponding regions iu the cricoid of Cogia. The anterior border slopes backwards rather abruptly as it approaches the ventral surface and meets the posterior border, which is practically horizontal, in a blunt angle; this angle nearly meets its fellow below the thyroid. The arytenoids appear to be closely similar to those of Cogia; there is no independent supra-arytenoid cartilage such as occurs in the Porpoise. The epiglottis has relations to the thyroid intermediate between the conditions found in Balcenoptera and Cogia, a condition in fact quite like that in the Porpoise. Its base rests against the upper margin of the thyroid, instead of pushing its way downwards between the two alse of that cartilage. I see no subepiglottid cartilage. The chief purpose for which I examined this larynx was with a view of ascertaining whether it presented any indications of the " median sac" described in some other Odontocetes, but there is no sign of this sac. The ridge, a cushion of the epiglottis, is continued beyond the cartilage in the form of a high membranous fold or septum, subdividing this part of the laryngeal cavity into a deep right and left pouch-much deeper than in Cogia-the lining of which |