Abschnürungen des Vorderendes sowie Farbendifferenzen desselben 

 gegen den übrigen Körper — das einzig Auffallende an der in Rede 

 stehenden Form — sind in dieser Gruppe der Landplanarien nicht 

 selten. 



Ich hatte gehofft, im British Museum noch eine zweite angebliche 

 Schnecke zu finden, von welcher es sehr wahrscheinlich ist, daß sie in 

 Wirklichkeit eine Landplanarie darstellt, nämlich Gu il ding' s Genus 

 Herpa aus Westindien. Indessen existiert das Originalexemplar nicht 

 in den Sammlungen des British Museum und die vorhandene Be- 

 schreibung 3 ist so wenig präcise, daß die Hoffnung aufgegeben werden 

 muß je darüber in's Klare zu kommen, ob Guilding eine Schnecke 

 oder eine Landplanarie vorgelegen. 



5. A study of Stenostoma leucops. 



ByH. N. Ott, Ph. M. 



eingeg. 9. October 1891. 



The preparation of the material, and the writing of the paper un- 

 der the above title, were done in the Zoological Laboratory of the 

 University of Michigan under the direction of Prof. J. E. Reighard. 



The paper is to be published in the American Journal of Morpho- 

 logy, but since a considerable time must elapse before publication the 

 following outline of results is submitted. 



As to the form, size and general structure of the body my results 

 agree with those of former writers. 



My observations on the structure and arrangement of the different 

 elements of the integument agree with those of earlier observers, 

 except as to the arrangement of the circular and longitudinal muscle 

 fibres. The circular fibres , rather than the longitudinal , were found 

 to lie next to the epithelial cells. Karyokinetic figures were observed 

 in the epithelial cells. 



The parenchyme is made up of two substances, a network and 

 a perivisceral fluid. As Böhmig states for Triclads and surmises for 

 some Rhabdocoels the network of the parenchyme is formed by the 

 fusion of individual cells which are connected by branching and ana- 

 stomosing processes (Gerüstsubstanz) and are separated by inter-cel- 

 lular vacuoles, which vacuoles are filled with the perivisceral fluid 

 (Saftplasma) . 



The alimentary canal is divided into two parts: pharynx and 



3 Siehe darüber bei W. Elliot »Description of a new Sepcies of Terrestrial 

 Planaria [PI. lunata]». Madras Journal of lit. and science, vol. XV, 1848 — 1849, 

 p. 166. 



