ORNITHOKHYSCHID.E. MAMMALIA. TACHYGI.OSSID.E. 



219 



The Duck-bill feeds on small molluscous animals, 

 various aquatic larvae, and especially on water-bugs 

 belonging to the genus Nattcoris, which abound in 

 the running streams and lakes of Australia. The most 

 interesting account of the habits of this animal yet 

 placed on record, is that given by Mr. Bennett in the 

 first volume of the Zoological Society's Transactions. 

 Speaking of one which he kept in a semi-captive state, 

 occasionally tethering it to a stake by the river's side, 

 he tells us that " it was exceedingly lively, swam in 

 the centre of the stream, and appeared in excellent 

 health and spirits. The water at one part of the 

 river being very clear, I saw its movements distinctly 

 under the water. On diving, it sank speedily to the 

 bottom, swam there for a short distance, and then rose 

 again to the surface ; it ranged the banks, guiding itself 

 in its progress according to the impressions received by. 

 the mandibles, which appeared to me to be used by it 

 as very delicate organs of touch. It seemed to feed 

 well ; for whenever it inserted its beak into the mud 

 it evidently procured some food from thence, as, on 

 raising the head, after withdrawing the beak, the man- 

 dibles were seen in lateral motion, as is usual when 

 the animal masticates. Although several insects were 

 basking and fluttering about the surface of the water, 

 close to it, no attempt was made to capture them, either 

 from its not seeing them, or from its preferring the food 

 which the mud afforded. The motions of the mandi- 

 bles in this animal, when seeking its food in the mud 

 and water, are the same as those of a duck when feed- 

 ing in similar situations. After feeding it would lie 

 sometimes on the grassy bank, and at others partly in 

 and partly out of the water, combing and cleaning its 

 coat as usual with the claws of the hind feet. After 

 permitting it to swim, feed, and clean itself for an 

 hour, it was replaced, although with great reluctance 

 on its own part, in its box ; it did not, however, as 

 before, betake itself to repose, but commenced and 

 continued a scratching on the sides of the box." 

 During sleep the duck-bill rolls itself up in the form 

 of a ball. For this, and many other interesting 

 facts, we are indebted to Mr. Bennett, who has also 

 given us a full account of the form and extent of the 

 burrows which these animals construct in the banks 

 of rivers. One of these burrows measured fully 

 twenty feet in length. It commenced in some long 

 grass about five feet from the water's edge, passed 

 upwards in a serpentine direction, terminating near 

 the surface of the ground in a rounded excavation, the 

 lower part of this hollow forming a nest x>f dried grass 

 and weeds. In this particular burrow Mr. Bennett 

 captured an unlucky ornithorynchus, which, on being 

 drawn out by the leg, manifested the most alarming 

 evidences of fear, its heart palpitating violently. It did i 

 not scream, or make any attempt to bite ; during its j 

 subsequent captivity, however, it frequently uttered a 

 soft growl during the night, at which tune it also made ; 

 vigorous efforts to escape. 



FAMILY IL TACHYGLOSSHX3E. 



The members of this family are at once distinguished 

 from the former by the mixed spinous and hairy char- 

 acter of their fur, as well as by the circumstance of 

 their possessing a slender subulate muzzle and a merely 

 rudimentary tail. On closer examination we find that 

 the jaws are entirely edentulous, the palate being 

 armed with several rows of small spines directed 

 backwards. A more significant character is founded 

 on the form of the tongue, which is long, narrow, 

 rounded, and very extensile hence the family name 

 above given closely resembling the lingual organ in 

 their placental representatives, namely, the true ant- 

 eaters and pangolins. The pentadactylous feet are 

 short and thick, the digits being furnished with power- 

 ful falciform claws adapted for burrowing. The second 

 aud third digits of the hind feet are particularly long. 

 The stomach is simple, capacious, and spherical when 

 distended. The coecum is moderately developed. 



THE POBCTJPLNE ANT-EATER (Tachyglotwu Hys- 

 trix), or AUSTRALIAN HEDGEHOG of the colonists, is a 

 native of New South Wales and Van Diemen's Land, 

 but is now rather rare in the first named locality. It 

 is maintained by some, on grounds apparently tenable, 

 that the forms proper to the two habitations are 

 distinct species; but others consider the differences 

 observable insufficient to prove a separate origin. 

 Without offering a positive decision, we strongly incline 

 to the belief that they are different annuals, the form 

 known as the Van Diemen's Land species (Tachyglossus 

 setosus) which, however, is not peculiar to that island, 

 according to the testimony of Mr. Waterhouse being 

 provided with small and narrow digits, as compared 

 with those of T. Hystrix, whilst the hairy appendages 

 of the skin are also longer, the spines, on the other 

 hand, being relatively short. Other minor differences 

 likewise exist. These animals are about the size of 

 our common hedgehog, varying in length from fourteen 

 to eighteen inches. The hairy portion of the skua 

 exhibits a chestnut colour, the spines being whitish 

 except at their tips, which are black. Like hedgehogs, 

 they roll themselves up when attacked on the open 

 ground ; but their safety is usually more effectually 

 secured by burrowing in the earth, or by entering a 

 previously constructed tunnel. These animals feed 

 upon ants, captured by the protrusion and subsequent 

 retraction of their extensile glutinous tongues, after 

 the manner previously described in our account of the 

 typical edentate ant-eaters or myrmecophagas. 



Those who desire more extended information respect- 

 ing the structure and economy of the monotreme mar- 

 supials, are referred to Professor Owen's elaborate 

 article " Monotremata," contained in the third volume 

 of Dr. Todd's Cyclopaedia of Anatomy and Physiology ; 

 and also to Mr. Gould's large folio work on the 

 " Mammals of Australia." 



END OF MAMMALIA. 



