8 On Lepidosiren articulata and Lepidosiren paradoxa. 



wise a simple un segmented cartilaginous rod. In Lepidosiren 

 articulata, on the other hand, this portion of the skeleton is 

 distinctly segmented, and that, too, in the case of the anterior 

 as well as the posterior limb ; the segments are largest in the 

 basal part, and diminish in size towards the tip. In the case 

 of the male of this species the basal segment in the posterior 

 limb is strikingly enlarged and slightly bent ; the terminal 

 joints which succeed it are small, and, taken together, convey 

 the impression of a jointed ray situated upon a larger basal 

 segment. This peculiar condition must, however, be tested 

 by the examination of a larger series of specimens, since in 

 the individual instance in question the structure may be due 

 to an injury which has afterwards healed. 



With regard to the internal organization, I am at present 

 only able to state that the faveolate connective tissue figured 

 by Hyrtl as existing in the anterior portion of the body occurs 

 at a similar spot in Lepidosiren articulata, but is also found 

 in the posterior region outside the peritoneum. I am inclined 

 to suspect that the tissue in question constitutes lymphatic sacs. 



The appearance of the organs lying in the body-cavity of 

 the female of Lepidosiren articulata does not seem to me to 

 agree with the figure given by Hyrtl. The ovaries, which 

 are apparently metamerically constricted, are enveloped longi- 

 tudinally in a fold of yellow fat, and thus remind the observer 

 of the similarly situated testes of the male animal. The 

 difference between what I have observed and Hyrtl's repre- 

 sentation is, however, probably a physiological one. It is to 

 be presumed that the specimen dissected by the distinguished 

 Viennese anatomist was a female at the period of complete 

 sexual maturity, in which the fatty masses had disappeared, 

 while the animal which I opened possessed ovaries which 

 were far from being mature, but had stored-up masses of fat 

 instead. 



For the present we arrive at the following diagnoses for 

 the two species : — 



Lepidosiren paradoxa, Fitz. 



Coat of scales distinct ; snout conical ; nasal apertures 

 transversely oval ; limbs with unsegmented cartilaginous axis. 



Lepidosiren articulata, sp. n. 



Coat of scales more or less concealed by thick epidermis ; 

 head and snout longer than in L. paradoxa, bluntly rounded 

 off in front; nasal apertures circular, with conical papilla j 

 limbs with segmented cartilaginous axis. 



