670 The American Naturalist. [July, 
the oppa fauna of Eastern Africa whenever a thorough search 
can Le made. 
The collection includes thirty-four species, of which twenty are 
lizards, twelve are snakes, and two are batrachians. Two plates, 
admirably drawn, accompany the paper, giving in detail the curious 
appearance of the three new species. 
The other papers contain a description of a new snake (Atractaspis 
leucura) from Assinie ;" a review of the genius Heterolepis, with the 
addition to it of three new species, —H. stenophthalmus, H. guiralit, H. 
savorgnanii ; and descriptions of snakes” and reptiles” from the 
Congo country. 
Of the latter, M. Mocquard described thirty-four species, four of 
which are new,—JA“icrosoma fulvicollis, Coronella longicauda, Atheris 
anisolepis, and Gontonotus brussauxii. 
r ; EMBRYOLOGY.: 
Development of Compound Ascidians.—Dr. M. v. Davidoff 
has published a second contribution to the above subject, entitled 
“ Untersuchungen zur Entwicklungsgeschichte der Distaplia magni- 
larva, etc.’’? He deals here with the general formation of the germ- 
layers. The paper runs through more than a hundred pages, and the 
author by no means confines himself to the title of the paper, but dis- 
cusses the development of all other Ascidians, the problem of the meso- 
derm formation, and touches upon the origin of the vertebrates them- 
selves, The holoblastic segmentation of the egg is described for the 
earlier stages. The most interesting fact in this connection is the 
presence of the est cells between the segments of the egg for quite a 
long time during the early stages. Subsequently they disappear, pre- 
sumably degenerating. A solid mass of cells results from the segmen- 
Sur une nouvelle espèce d’Atractaspis (4.ewcura). Ext. Bull. de la Société 
Philomatique de Paris Séance du 28 Novembre, 1885. 
‘8 Du genre Heterolepis et des espèces qui le np tO dont trois nouvelles. Ext. 
Bull, de la Société Phildémathique de Paris, October, 1 
19 Sur les Ophidiens rapportés du Pai par la Mission du Brazza. Ext. du Bull. Soc. 
Philomathique de Pari ce dur 1886, 
20 Sur une Collection de Reptiles pitta Ext. Bull. de la Soc. Philomathique de 
la Paris, 8 serie, t. r, No. 4, page 143. 
1 Edited by Dr. T. H. Morgan, Johns Hopkins University, Baltimore, Md. 
2 Neaples Mittheilungen, IX. Band, IV. Heft. 

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