308 Dr. J. Murie on the Shin cCr. of the Rliytina. 



There is an organic structure which maj be separately 

 mentioned, as misconception at one time existed regarding its 

 function and homology ; I allude to the jaw-plates. The pa- 

 latine or premaxillary mass, and mandibular plate, from their 

 density and situation, Steller appears to have considered a 

 kind of striated bony tooth-representative (/. c. p. 302, " Sed 

 duobus ossibus validis, candidis, seu dentium integris massis." 

 "Oris striati ossis"). Others have been inclined to look 

 upon these manducatory laminee as the homologues of the 

 baleen-plates of Cetacea. 



It is to J. F. Brandt that we are indebted for a correct 

 notion of their intimate structure and a distinct conception of 

 their true homology. A fragment of a cranium in the Zoolo- 

 gical Museum of St. Petersburg, with part of the said plates 

 in sitUj enabled that anatomist to institute a thorough micro- 

 scopic investigation of their minute texture &c. In his 

 ' Symbolee Sirenologica^,' laid before the Imperial Academy, 

 January 1845, published 1849, he has demonstrated the cel- 

 lulo-epithelial and partly tubulo-papillar nature of the plates, 

 and justly correlated them with the horny tuberculate plates 

 in the mouths of the Dugong and Manatee. 



With Prof. Brandt's views I heartily concur ; but I moreover 

 regard the upper of these plates as the precise equivalent of 

 the anterior palatine pad of ruminants &c. I even go further* 

 in tracing the homologue of the baleen-plates of Cetacea in 

 the Sirenian mouth in those bundles of hairs and bristles 

 which spring from the buccal aspect and angle of the mouth 

 of Manatics, the intervening papillae of the mucous membrane 

 corresponding to the "soft intermediate substance " betwixt 

 the baleen at its root — the combination of these structures, 

 their elementary composition, relation to each other, situation, 

 &c. agreeing in most particulars with the whalebone and its 

 basal matrix. 



In his capital description of the soft parts of the Long- 

 niddry whale. Prof. Turner f discusses the homology of 

 whalebone, and suggests its agreement with the transverse 

 folds of mucous membrane and fore pad in the palate of Ru- 

 minantia, more particularly citing the giraffe. So far as 

 regional proximity and textural constituents are concerned, 

 doubtless there is much to be said in favour of such a notion. 

 But in both toothed and toothless whales there is a rugose 

 thickening of the soft palate anteriorly, identical in position 



* See my forthcoming memoir, now in the press, " On the Form and 

 Structure of the Manatee," Trans. Zool. Soc, read November 1870. 



t "An Account of the Great Finner Whale (^Balanoptei-a Sibbaldii) 

 stranded at Longniddry," Trans. Roy. Soc. Edinb. 1870, vol. xxvi. p. 221. 



