266 PROCEEDINGS OF THE ACADEMY OP 



his work than the latter. He, nevertheless, regards the Sirenians 

 as most nearly related to the Pachj-derms, although entitled to 

 ordinal distinction, and even more distinct from tlie Pach3"derms 

 than are the Cetaceans from the Carnivores, Avhich are connected 

 hy intermediate forms {e.g. Zeuglodonts, Seals, and Sea-otters), 

 in this case of value and indicating affinity.' 



The analysis of the cited memoir gives the following results : 

 1st. Characters supposed to differentiate the Manatee from the 

 Cetaceans. 

 These may be arranged under tliree categories, viz: 

 a. Those really differentiating the Manatee from all the Ceta- 

 ceans, to wit: the form of the vertebnxi and the absence of ossified 

 epiph3'ses, the form of the scapula, the structure of the anterior 

 limb, the development of the occipital bone and the position of 

 the condyles, and the form of the lower jaw. 



h. Those not differentiating the Manatee from all the Cetaceans, 

 but from peculiar sub-orders of Cetaceans, viz., the absence of a 

 rostrum, position of the narial apertures, the presence of olfactory 

 nerves, the development of tlie nasal bones, and " the two bones 

 of the lower jaw [not] separate at the sympliysis." 



' (5) Sirenia in universum quidem nexum plus minusve propinquum 

 CU9 variis mammalium divisionibus nominutis, cum PacliydermatibuH potis- 

 simuni, habent (ita ut a reccntiorum phu'ibus adeo pro formis PacJii/denna- 

 tum aquatibilibus shit declarata). Forma; re vera intermedia; tamen 

 (qualem inter Mustelina et Phocacina genus Enhydris pra;bct) nee inter 

 Sirenia et Pachydennata, ucc inter Sirenia et Caiacea, nee inter Zeuglo- 

 dontes et Sirenia, nedum inter Phocacina et Sirenia hucuaquc sunt rcpcrta;. 

 Sirenia potius non solum a Cetaceis et Zeufjlodontibus et Phocinis, sed 

 etiam a Pachydermatibus niagis differunt quam Cetacea a Feris, quum 

 Cetacea Zeuglodontum ope Phocinis appropinquentur, Phocina vero Enhy- 

 dribus cum Mustelinis cnnnectantur. 



(6) Sirenia iguitur pro mammalibus mere aquaticis dcclarari potcrunt, 

 qua; corporis et plurium scclcti partium motubus aquatibus adaptorum 

 figura et structura Cetaceis et Zcvglodontibus sunt connata et Phocinis 

 parnm similia apparent, ob indolem phytopbagam (non ut in dictis mam- 

 malium divisionibus carnivoram) et strueturam morpbologicam ei con- 

 gruam vero Pachydermatibus muUo magis (piam aliis mammalibus aflinia 

 observantur, nibilominus tamen, ob cliarcclercs plurcs ijisis poculiares et 

 formarum intcrmcdiarum absentiam etiam Pachyderniatibm adjungi liaud 

 possunt, quare aptius, pro tempore saltcm, ordinem peculiarcm couslitue- 

 runt. Brandt, Symb. Siren., 18G8, p. 359. 



