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for the first described Australian species of Enteropneusta. It is specially 

 characterised externally by the great development of the genital wings which 

 completely hide the gill-area, and extend far into the hepatic region, and by 

 the presence of two longitudinal epidermal stripes overlying the two ciliated 

 bands of the intestine. In the mode of formation of the proboscis pore, it 

 appears to be the most variable of all Enteropneusta hitherto described. The 

 most interesting points in its internal anatomy are the presence of a median 

 longitudinal infolding of the ventral wall of the heart bladder into the cavity 

 of the same, the presence of a transverse vessel between the different pro- 

 boscis vessels, and the much branched condition of the gonads. — 9) On a 

 Platypus Embryo from the Intrauterine Egg. By J. P. Hill, Demonstrator 

 of Biology, and C. J. Martin, M.B., B.Sc. (Lond.), Demonstrator of Phy- 

 siology, in the University of Sydney. The embryo described was taken from 

 one of two eggs just ready to be laid. The eggs measured 18 mm. by 

 13 '5 — being somewhat larger than the eggs described by Caldwell. The em- 

 bryo was found lying on the surface of a thin-walled vesicle with its long 

 axis corresponding to the long axis of the egg. It measured 1 9 mm. in length 

 from the anterior end of the medullary plate to the posterior end of the 

 primitive streak. The vesicle on which the embryo lay consisted of two layers 

 all over, with the mesoderm extending about half-way round between and 

 comparable to a typical mammalian blastodermic vesicle. The vesicle filled 

 the whole of the egg, and contained a thin albuminous fluid together with a 

 thin layer of yolk spheres next its wall. The embryo, with the exception of 

 a slight head-fold, is quite flat. Medullary folds are absent except in the 

 most anterior region of the future fore-brain, where slight lateral upgrowths 

 of the medullary plate appear. The three cerebral vescicles are indicated, 

 and in the region of the hind-brain four well-marked neuromeres exist. 

 External to the 2nd, 3rd and 4th neuromeres is an extensive auditory plate, 

 already slightly grooved. There are seventeen somites, which in the middle 

 region of the trunk possess distinct cavities, and externally to these from the 

 4th to the 17th are situated the Anlagen of the Wolffian bodies. At the 7th 

 somite Wolffian duct is first seen, the appearance of which in sections sug- 

 gests an ectodermal origin. Double heart Anlagen are present, but there is 

 no trace of vascular area besides a slight mottling in and around the area 

 pellucida. A distinct blastopore is present with a neurenteric canal which 

 runs through the head process and opens into the archenteron (yolk-sac 

 cavity) . The primitive streak extends behind the blastopore to a distance 

 of 1-5 mm. The embryo more nearly resembles that of the Virginian Opos- 

 sum (Didelphys) of 73 hours, described by Selenka, than any other embryo 

 known to the authors. The Platypus embryo is, however, much longer. • — 

 Mr. A. Sidney Olliff sent for exhibition a number of specimens of a species 

 of Psylla from Jarrahdale, W. Australia, which makes elongate, semi-trans- 

 parent, horny, larval coverings, or tests, on the foliage of the Flooded Gum 

 [Eucalyptus rudis). In structure and habits the species in closely related to 

 Psylla eu'mhjpti, Dobs., recorded from Tasmania ; and economically it is of 

 importance as it sometimes occurs in such numbers as to cause serious injury 

 to its food-plant, a usefull West Australian timber. The insect was collected 

 by Messrs. AV. Paterson and A. Despeissis, and it is proposed by Mr. Olliff to 

 call it Psylli 2)enculosa. — Mr. Edgar R. Wait e exhibited specimens of the 

 snake Jspidites ramsayi described in his paper; a Golden Perch Ctenolates 



