46 Mamm. 
II. MAMMALIA. 
two hearts examined bj him the septal flap of this valve was com- 
plete, though less conspicuous than the free flap, owing to the fact 
that it had either no papillary muscles attached to it, or that the 
muscles were very small. 
Poulton, supra, p. 17, discusses the nature of the beak and hairs. The 
so-called dumbbell-shaped bone is shown by Wilson, suprd, p. 23, 
to be vomerine, rather than premaxillary in origin. 
2. EciIIDNIDiE. 
In describing the young, Parker, P. Zool. Soc. London, 1894, pp. 3-14, 
states that it resembles that of Omithorhynchus in the following 
points : — (1) In the possession of a thick horny layfcr covering the 
snout, as well as horny teeth, and a horny caruncle for breaking open 
the egg-shell ; (2) Glands resembling ordinary sweat-glands opening 
on the snout, as well as on the front of the palate ; (3) A highly 
developed Jacobson’s organ, comparable to that of the Squamata ; 
(4) A complicated maxillo-turbinal ; (5) A communication between 
the two nasal cavities ; (6) Numerous glands in connection with the 
pasal chamber and Jacobson’s organ. On the other hand, the follow- 
ing features are peculiar to Echidna , viz. : (1) The absence of any 
traces of tru$ teeth ; (2) The possession of a mammary pouch in the 
young female ; (3) The less solid nature of the nasal chamber, 
the development of the ethmo-turbinals, and the absence of trans- 
verse septa in the front of the nasal cavity ; (4) The slightly smaller 
size of Jacobson’s organ and its turbinal. It is concluded that 
Ornithorliynchus is the more primitive type of the two ; the young 
Echidna resembling the former much more than does the adult, and 
being very highly specialized as regards many characters j and that 
both genera are nearly allied. For structure of shell of egg, see 
Neumeister, supra , p. 15. 
INCEPTS SEDIS. 
fABDERITIDiE. 
iAbderites altiramis , n. sp., Ameghino, Bol. Ac. Cordoba, xiii, p. 340, 
Tertiary, Patagonia. 
t Metriodromus, n. g., arenarus and spectans , n. spp., Ameghino, t . c. 
pp. 342 & 343, ibid. 
iCallomenus ligatus and robustus, n. spp., Ameghino, t. c. p. 344, ibid. 
tEPANORTHIDJJ. 
t Epanorthus simplex , n. sp., Ameghino, t. c. p. 347, ibid. 
iMetaepanorthys, n. g., complicatus, n. sp., Ameghino, t. c. p. 348, ibid. 
iParaepanorthus, n. g., type P. minutus , Amegh.; Ameghino, l. c., ibid. 
iPrepanorthus , n. g., lanius , n. sp., Ameghino, t. c. p. 351, ibid. 
