ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
643 
Septal Musculature and the (Esophageal Grooves in Anthozoa.*— 
Herr O. Carlgren finds that Cerianthus Lloydii, G. membranaccus, and 
C solitarius bear longitudinal muscles on the side of the septa turned 
away from the directive pair, and transverse muscles on the side turned 
towards the directive pair. It seems that the Ceriantheae possess an 
anterior or dorsal (not ventral) oesophageal groove, while that of the 
Alcyonaria and Zoanthese is posterior or ventral. Of the two grooves 
in Edwardske and in most Hexactinia, the dorsal corresponds to an 
anterior and the ventral to a posterior. 
Brood-chambers in Actinise.t — Herr 0. Carlgren finds two types of 
brood-chamber. In one type the brood-chamber is formed from the 
gastrovascular chambers, or from the gastrovascular space itself (in an 
unnamed Paractid and Bunodid). In the other type there are in the 
lower part of the body-wall special cavities — -invaginations of the 
ectoderm — in which the embryos complete their post - embryonic 
development. 
Comparative Embryology of Scyphomedusse.J — Hr. A. Goette finds 
that Aurelia , Cotylorhiza , and Pelagia differ in their development only 
in degree. All three exhibit in their youngest larvss the essential struc- 
ture of Scyphomedusse, differing only in the degree of completeness with 
which the typical features are retained. 
The author begins with a description of the larvae of Cotylorhiza 
tuberculata. These exhibit an ectodermic oesophagus, four gastric 
pouches, and, indeed, all the essential characters of AwreZm-larvae. The 
oesophageal ectoderm extends to a portion of the gastric pouches, and 
over the four gastric folds. In Cotylorhiza there are four true septal 
funnels before the proboscis is developed. 
In Pelagia the mouth of the larva is to be found at the invagination- 
opening of the ectodermic gullet, and the prostoma at the base of the 
closed gullet, where the communication with the central stomach is 
formed. The ectodermic gullet forms the principal median portion 
of the gut ; the central stomach and the gastric pouches are alone 
endodermic. The tetrad segmentation defined by the first four 
gastric pouches is in entire agreement with the symmetry of Cotylo- 
rhiza. We cannot follow Goette through his account of the develop- 
ment, but his conclusion is that the larvae of Pelagia possess before 
the beginning of Ephyra-formation the most essential features of a 
scyphostoma. 
Early Stage of Distichopora violacea.§ — Dr. S. J. Hickson gives an 
account of the early stages in the development of Distichopora violacea . 
The result is the generalization that in the Stylasteridae there is no seg- 
mentation, no process of invagination to form the endoderm, and no process 
that can be compared with ordinary primary delamination. The author 
next discusses the formation of the germinal layers in the Coelentera 
generally, and gives the following plan : — 
* Ofversigt K. Vet. Akad. Forhandl. Stockholm, 1893, pp. 239-47 (2 figs.). 
t Tom. cit., pp. 231-8 (5 figs.). 
j Zeitschr. f. wiss. Zool., lv. (1893) pp. 645-95 (4 pis.). 
§ Quart. Journ. Micr. Sci., xxxv. (1893) pp. 129-58 (1 pi.). 
1893 . 2 Y 
