58 Dr. W. Djbowski on the 



early in the form of two long cords, which open close together 

 into the intestine in the region of the rectal section. Accord- 

 ing to this observation T do not hesitate to adopt Witlaczil's 

 view, according to which the green cell-mass in the abdomen 

 of the viviparous Aphides (which is likewise arranged into 

 two cords) represents the Malpighian vessels of other insects. 

 In a very pale Aphis-embryo I was able clearly to detect, 

 besides the very distinctly marked dorsal vessel, the point of 

 convergence of the two cords, but without distinctly seeing the 

 point of discharge (as in Coccus hesperidum) . 



The &g^ of the viviparous Aphides, for which I have here 

 and there, for convenience' sake, employed the antiquated 

 term " pseudovum," therefore presents exceedingly interesting 

 and very distinctly observable developmental processes, which 

 cannot be sufficiently studied. In recent times Dr, Arnold 

 Brass* (of Leipzig) and Dr. Ludwig Willf (of Kostock) 

 have occupied themselves with the earliest stages of develop- 

 ment. The last-mentioned gentleman has also already an- 

 nounced the publication of a work upon the later stages of the 

 Aphis-embryo. In course of time many other workers will 

 certainly have to be registered for this highly interesting 

 subject. 



VII. — Notes on the South-Russian Spongillidge. 

 By Dr. W. Dybowski \. 



Dr. p. T. Stepanow, Professor of Zoology in the University 

 of Charkow, has had the kindness to send me some specimens 

 of the freshwater sponges for scientific investigation. The 

 sponges preserved in the Museum of the above University 

 and those collected by Prof. Stepanow himself are from the 

 following localities : — 



1. From the river Udy (a right affluent of the Siewiernyj 

 Daniec), Gov. Charkow. 



2. From Lake Lebiedin (Circle Lebiedin), Gov. Charkow. 



3. From the river Kolomak (left affluent of the Worska, a 

 branch of the Dnieper), Gov. Poltawa. 



* " Das Ovarium uud die ersten Eutwicklungsstadien des Eies der vivi- 

 pareii Aphiden," in Zeitscbr. f. Naturwis*. Bd. iv. (1882). 



+ " Zur JBildung des Eies iind des Blastoderms bei den viviparen 

 Apliiden,'' in Arbeiten des Zool. Instit. zu Wiirzburg, 1883, Heft :'>. 



X Translated by W. S. Dallas, F.L.S., from the ' Sitzungsbericlite der 

 Naturforscher-Gesellscbaft bei der Univeisitat Dorpat,' Bd. vi. pp. SOT- 

 SIS (1884). 



