332 Prof. Owen's Description of the Lepidosiren annectens. 



big as the largest scales, chiefly confined to the tail : the mucous pores and 

 lines were black. 



Such are the general external characters of the Lepidosiren annectens, in 

 most of which it agrees with the Lepidosiren paradoxa. It is not, however, 

 a whit less paradoxical than its earlier described congener ; and it may be 

 truly said, that since the discovery of the Ornithorhynchus paradoxus there 

 has not been submitted to naturalists an animal which proves more forcibly 

 than the Lepidosiren the necessity of a knowledge of its whole organization, 

 both external and internal, in order to arrive at a correct view of its real 

 nature and affinities. 



It was the reluctance to bring before the notice of zoologists an incomplete 

 description of this form, which has prevented my being the original proposer 

 of the genus, having recorded its principal characters as the type of a new 

 genus of abdominal malacopterygious Fishes in the MS. Catalogue of the Mu- 

 seum of the College of Surgeons, in June 1837, under the name of ' Protopte- 

 rus,' in reference to the rudimental or embryonic condition of the fins, and 

 with the specific name of anguilliformis as indicative of its forming a transition 

 from the abdominal to the apodal orders. The subsequent reception of Dr. 

 Natterer's memoir in February 1838, rendered it necessary to substitute another 

 generic and specific name, since the species described by that enterprising and 

 scientific traveller presented still more eel-like proportions. 



The anatomical details which form the subject of the remaining part of the 

 present memoir, while they confirm the propriety of referring the genus Lepi- 

 dosiren to the class of Fishes, lead to more enlarged and juster views of its affi- 

 nities both to the members of that class and to the higher Vertebrate animals. 

 To the description of these details I now proceed. 



Osseous System*. 



The skeleton of the Lepidosiren is partly cartilaginous, partly bony ; the 

 ossified portions are of a green colour, like those of the Gar-pike {Belone vul- 

 garis). The bodies of the vertebrae retain the primitive condition of a conti- 

 nuous cylindrical gelatinous chord, with an external ligamentous sheathf, 

 except in the caudal region, where they present a cartilaginous firmness, with 



* Tab. XXIII. figs. 4, 5, 6, 7. f Tab. XXIV. fig. 2, a. 



