128 Miscellanea us . 



water shells in this country who have not the opportunity of con- 

 sulting scientific libraries, and to these a book like the present is 

 particularly welcome. 



The printing, paper, and general appearance of the work are all 

 that can be desired ; the figures, as a whole, are very good indeed, but 

 to state beneath each by whom the specimen was collected appears 

 rather unnecessary, being practically of no interest whatever to the 

 general student, although perhaps gratifying to the individuals 

 named, especially when the same illustration is employed several 

 times and the personal information is repeated in each instance. 

 The coloured plate, produced by chromo-lithography, is also very 

 successful ; the outlines of the different forms repi-esented exhibit 

 great accuracy, and the coloration is not exaggerated. 



Considering the need of such a work, the style in which it is 

 issued, and the completeness aimed at, there seems every proba- 

 bility of its gaining a wide circulation, and, in fact, superseding all 

 previous works on the subject. 



MISCELLANEOUS. 



On tlie Embryology of Gebia littoralis *. B}' P. Butschinsky, 

 of the University of Odessa. 



So long ago as the year 1882 a segmentation of the ova of 

 Callianassa, belonging to the family Thalassinida^, was described 

 by C. Mereschkowski f. I am now in a position to furnish a com- 

 plete account of the development of Gebia littoralifs. The definite 

 facts which I have obtained supplement in many respects the con- 

 ception of the embryonic development of the Decapods as it is 

 generally represented. 



The ova of Oebia % possess a great abundance of food-yolk. The 

 initial segmentation takes place with them in the interior of the 

 ovum ; the first segmentation nucleus divides, together with the 

 accumulation of protoplasm surrounding it, into two, four, and eight 

 segmentation nuclei. All these nuclei travel towards the surface of 

 the ovum. The food-yolk takes no share in this process ; it com- 

 mences to collect more closely round the nuclei, and partly unites 



* I shall publish in Russian a complete memoir on the development of 

 Gebia in the ' Memoires de la Soci^te des naturalistes de la Nouvelle- 

 Russie a Odessa.' 



t C. Mereschkowski, '^Eine neue Art von Blastodermhildung bei den 

 Decapoden," Zool. Anz. v. Jahrg. no. 101 (1882). 



X For fixing the ova I have employed boiling Perenyi's and Kleinen- 

 berg's solutions, or alcoholic sublimate solution. The best staining 

 reagents are Grenacher's borax-carmine, Kleinenberg's bfematoxylm, and 

 hsematin-alum. The objects after being saturated with evaporated 

 photoxylin and stained, were placed in a mixture of chloroform and 

 paraffin at a temperature of 40°-45 C, and then in pure melted paraffin. 



