52 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
also placed in independent communication with each commissural gang- 
lion by elements which originate in cells of the latter, and run through 
the oesophageal ganglion. 
Homarine Origin of Brachyura.* — M. E. L. Bouvier is satisfied 
that Crabs are directly derived from the Homaridse, and probably from 
those of the Jurassic epoch. The most primitive abyssal Dromiid which 
he has studied is Homolodromia jparadoxa ; it has a resemblance to the 
Macrura and the Anomura in its elongated carapace, its widely open 
orbits, and its rostrum independent of the epistome. In a number of 
other characters it differs from the Galatheidse and Axiidae, and has a 
closer resemblance to the Homaridae. The mass of common characters is, 
indeed, so large that it seems to him impassible to doubt that the Homo- 
lodromiae are derived frem the Homaridae, though from Homaridae more 
primitive than any now existing ; from forms, that is, that had preserved 
all the anterior arthrobranchs found in their ancestors, the Penaeidae. 
Sound produced by Ocypoda ceratophthalma.f — Dr. A. R. Ander- 
son describes the means by which this Crab produces a loud croaking 
noise, closely resembling that of frogs ; the burrows formed by the 
animals are, further, so constructed as to act as excellent resonators. 
Entomostraca and the Surface-Film of Water.f — Mr. D. J. Scour- 
field remarks that, although it has long been recognized that the curious 
physical properties possessed by the surface-film of water render it of 
considerable importance to many of the smaller aquatic animals, the 
question of specific relation has been somewhat neglected by naturalists. 
The author is led by his observations to conclude that to large 
numbers of Cladocera and Ostracoda this surface-film is a very dangerous 
element in their environment ; to others, on the other hand, it affords 
peculiar advantages ; this is the case with a few specially modified 
Cladocera and Ostracoda, and some Copepoda, which do not present any 
apparent structural modifications. In nearly all cases the relation to 
the surface-film, whether beneficial or not, depends on the same physical 
principles — the upward pull of the surface-film when forming a capillary 
depression, and the possession by the animals of water-repellent shells, 
ridges, scales, or setae, capable of penetrating the surface-film, and 
producing capillary depressions. 
Freshwater Copepoda.§ — Dr. A. Mrazek calls attention to the 
variability of the characters generally used to establish species of fresh- 
water Copepods, and next proceeds to discuss the Copepod-fauna of 
Bohemia ; no less than 47 species of Copepods are enumerated, eight 
of which are new. The abnormal characters of some examples are 
described and discussed. 
Annulata. 
Abnormal Annelids. |j — Mr. E. A. Andrews records several cases of 
doubling of the posterior end of Allolobojphora foetida and Podarke obscura. 
* Comptes Rendus, cxix. (1894) pp. 656-8. 
f Joum. Asiat. Soc. Bengal, lxiii. (1894) pp. 138 and 9. 
X Journ. Linn. Soc. Lond., xxv. (1894) pp. 1-19 (2 pis.). 
§ Vgstnik Spol nauk v Prage, 1893, 74 pp. 3 pis.; see Zool. Centralbl., i. (1894) 
pp. 593 and 4. 
|| Quart. Journ. Micr. Sci., xxxvi. (1894) pp. 435-60 (3 pis.). 
