POLCASE a ilies 
MEDUSINA DEPERDITA (p. 91). 
Fia. 1. Plaster impression of a limestone slab from the lithographic slates of Hichstidt (white 
Fig. 2. 
Jura coral limestone), with an impression of Medusina deperdita. The medusa is drawn 
to the natural size. (After Haeckel.) 
+. Marginal canal (ring canal in the umbrella rim). 
. Expansion in the middle of the radial canal (genitalia?). 
. Mid-field of the medusa impression, corresponding to the stomach and mouth. 
. Periphery of the gelatinous mantle (margin of the impression). 
*, Radial canals. 
. Shallow circular furrow in the slab surrounding the impression of the periphery of the 
mantle. 
. Broader ring about the disk ring (thickness of the gelatin substance of the medusa which 
has been pressed flat). 
ACRASPEDITES ANTIQUUS (p. 79). 
A limestone slab from the lithographic slates of Hichstadt, with an impression of Acraspe- 
dites antiquus. The diameter of the figure is in relation to the original as5 to7. (After 
Haeckel. ) 
*, Marginal canal (ring canal in the umbrella rim). 
g. Lobe-shaped elevation, rising from the mid-field, between each two radial canals (genitalia?). 
. Periphery of the genital mounds. 
j. Indentation of the umbrella edge, corresponding to the anastomosis of each radial canal 
into the marginal canal. 
,. Mid-field of the medusa impression, corresponding to the stomach and mouth. 
p, Periphery of the gelatinous mantle (margin of the impression). 
*, Radial canal. 
s. Shallow circular furrow in the slab surrounding the impression of the periphery of the 
mantle. 
MEDUSINA PORPITINA (p. 95). 
Fia. 3. (After Haeckel.) See description in text. 
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