G22 



Die nicht zu bedeutenden Besonderheiten und Abweichungen in 

 der P/trynocep/ialun-'Entwicklung von der der Lacerna- Arten werden in 

 meiner russischen Abhandlung dargelegt. 



Kasan. August 1888. 



4. Psorospermium Lucernariae. 



By Rupert Vallentin, Falmouth. 



eingeg. 2. October 1888. 



I have read with much interest the remarks on Psorospermium 

 Haekelii inZool. Anz.No. 270 by Dr. Otto Zacharias, and in No. 278 

 by Dr. A. Wierzejski. 



It is my intention briefly to describe a specimen of sporozoon 

 which I first met with during August 1887 in the tissues of Lucernaria 

 auricula. My remarks are I regret to say incomplete , but still I ven- 

 ture to hope will not be devoid of interest, as, so far as 1 am aware, it 

 has never been described before; and to which I have given the above 

 name provisionally. 



When beginning the examination of this Hydrozoon — with the view 

 to study its development, — I noticed in several, — and in some cases 

 many — small, white, spherical masses, irregularly scattered along the 

 margin of the inner wall of the umbrella ; and varying in size from ^/oq 

 — i/j,o of an inch in diameter. 



In a few specimens of L. cyathiformis — which is rare — 1 have 

 counted as many as thirty distinct psorosperm masses in a single indi- 

 vidual. In these specimens the psorosperm masses are not confined to 

 the inner wall of the umbrella , but are irregularly scattered throughout 

 the «structureless layenf, but never present in the pedicle. I am in- 

 clined to imagine that in these, the fact of the psorosperm masses beini^ 

 so abundant, coupled with the invariable presence of the free amoeboid 

 bodies in the tentacles, the well being of the host is considerably af- 

 fected ; for, on examination of fresh specimens the margin of the um- 

 brella bearing the tentacles is thrown further back. I found also that 

 a stimulus — in the shape of a needle point — applied to the margin 

 of the umbrella the «latent period« was decidedly longer than in a spe- 

 cimen of L. auricula. For want of proper appliances I am unable to 

 give the exact difference. 



On examining the contents of a psorosperm mass one finds the 

 spores therein in various stages of development. There is no definite 

 membrane separating the spores from the »structureless layer« of its 

 host. The youngest stages consist of a spherical mass of protoplasm, 



