t 1032 General Notes. . . N 
as a hyaline, structureless formation. Each end organ connects 
with a nerve-fibre, which in turn leads back to a unipolar cell of — 
the optic ganglion. No lens is to be recognized in the sections. 
In Vorticerus auriculatus the two eyes (which lie directly on the 
brain) have the optic cavity divided into two chambers by a — 
middle pigmented wall. Each cavity is filled by fine rods, leav- _ 
ing a central canal free. Around the margin of the capsule are 
numerous cells, which resemble ganglion-cells, and which se 
fibres to the rods, and hence are regarded as retina-cells. 
> nati a ki 
A Parasitic Rotifer—Nearly twenty years ago E. Ray Lan- 
kester briefly described and roughly figured a rotifer, which he 
found parasitic in the body-cavity of Synapta from the Island of 
Guernsey. Recently Dr. Zelinka has found the same form m — 
the Adriatic, and describes it as Discopus synapte nov. gen. et sp. 
According to the latter author this is not an endo-parasite, but 
lives in folds of the skin of the Synapta, and from these large 
numbers may be taken by a pipette. The animal belongs to the 
Philodinidæ. Zelinka has been able to stain and section these 
animals, and describes their internal structure in some deta 
His conclusions are (1) that the bilobed wheel of the Philo- 
dinide can be homologized with the ciliated band of the trocho- 
sphere, (2) that the anterior end of the outstretched body z 
homologous with the “ scheitelplatte,” and (3) that the brain 0 
the, rotifer arises partly from separation from th 
ane partly from immigration of primitively peripheral 
cells, 
bed the 
to the 
; f the 
same genus have been described from all parts O ugh al 
La 
(Zoologische Fahrbuch, ii, 1887) Dr. J. G. de Man has ader 
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2 
Preliminary Notes on the Osteology of Alosa rar ly de 
oe —In the shad the muscle of the lateral line is very RES 
oo ed, and extends down quite deeply between "e tissue 
_ ventral masses of the lateral muscles. In the conn 
