2(56 



It is remarkable that in Limufas (in Trilobiics also) the eyes are 

 always on the ventral side of the line of demarcation between the dor- 

 sum and the ventrum, and that spines are always on this line (in Li- 

 mulus spines are found on the dorsal median line also, but they are in 

 the dorsum only . 



5 Nervous-System. — The nervous-system arises from a paired 

 longitudinal thickening of the ectoderm. The anterior ends of these 

 thickenings are much broader than the posterior parts, and there are 

 two pairs of the ectodermic invaginations. These parts form the brain. 

 About 24 days after fertilization, 9 pairs of ganglia may be seen (there 

 is a pair of them in the segment of the metastomaj. They are separa- 

 ted from the general ectoderm from the anterior end gradually. From 

 the 3rd pair of ganglia backwards there is a lateral commissure in each 

 segment. The brain has one transverse commissure. The separation 

 of the brain from the general ectoderm is later than that of ganglia. 

 There is a peculiar grouping of the nuclei, as that found in the retinal 

 portion of the eye , in the nervous system before it is separated from 

 the general ectoderm. 



6) Eyes. — The eyes are developed from pre-oral ectodermic in- 

 vaginations, externally to the brain. They are produced at the margin 

 of the ventral plate, and retain this position ; therefore they are after- 

 wards found in the dorsal surface of the body by the reflection of the 

 ventrum. The lateral eyes, moreover, migrate posteriorly, hence 

 many authors have wrongly supposed them to belong to a thoracic 

 segment. The invagination of the lateral eyes is soon obliterated. The 

 median eyes originate from a pair of little ectodermic invaginations. 

 These invaginations are afterwards united into a tube and the tube is 

 subsequently reduced to a solid rod , the distal end of which is enlar- 

 ged and lies always at the margin of the ventrum and the dorsum. 



Tokyo, 13. April, 1891. 



6. Schizocerca diversicornis Daday oder Brachionus amphifurcatus Imhof? 



Eine synonymische Bemerkung. 



Von Dr. E. von Daday, 



Docent an der Universität in Budapest. 



eingeg. Tò. Mai 1891. 

 O. E. .Imhof äußert sich anläßlich der Bemerkungen über 

 die »Liste des Rotiferes observes en Galicie« betitelte Notiz A. 

 W i er zej ski's bezüglich der Schizocerca diversicornis v. Daday wie 

 folgt: »Diese Rotatorienform wurde in den Materialien von Weltner 

 in Berlin aus norddeutschen Seen gefunden und im Zoolog. Anzeiger 



