94 FOSSIL MEDUS%. 
MEDUSINA BICINCTA Haeckel. 
Pl. XLV, fig. 2. 
Medusites bicinctus Haeckel, 1869. Zeitschr. fiir wiss. Zoologie, Vol. XTX, pp. 554-555, 
561, Pl. XLII, fig. 3. 
Medusites bicinctus Haeckel, 1880. System der Medusen, p. 648. 
Medusites bicinctus Ammon, 1886. Abhandl. Math.-phys. Classe Konig]. bayerischen 
Akad. Wiss., Vol. XV, p. 158. 
The impression of this medusa is very weak and only with difficulty can the out- 
lines be distinguished of a central cruciform figure surrounded by two circular zones. 
At first sight this form appears to be an example of Medusites (Trachynemites) deper- 
ditus, but by a more careful inspection essential differences become apparent. In the 
first place, the external circular zone is not simple, but double, and, secondly, the 
eight radial lines of the mid-field lie at alternately unequal intervals. 
The interpretation of this very obscure configuration is difficult and uncertain. 
The external of the two peripheral rings (wv) is probably to be referred to the thickness 
of the gelatinous disk ; the inner (c) either to a very broad ring canal or to a strong 
velum. The four narrower of the eight three-cornered facets of the mid-field (7) are 
probably to be interpreted as four radial canals, widening toward the periphery, the 
four broader ones as interradial areas.’ 
MEDUSINA STAUROPHORA Haeckel. 
Pl. XLII, fig. 3. 
Medusites staurophorus Haeckel, 1869. Zeitschr. fiir wiss. Zoologie, Vol. XIX, pp. 
555-556, 551, Pl. XLII, fig. 6. 
Medusites staurophorus Haeckel, 1880. System der Medusen, p. 648. 
Medusites staurophorus Ammon, 1886. Abhandl. Math.-phys. Classe Koénigl. baye- 
rischen Akad. Wiss., Vol. XV, p. 158. 
The outline of the disk of this medusa is so faint as to be scarcely discernible. 
It appears to form a circle with a diameter of 50™™; 6™" from this runs another con- 
centric circle, just as indistinct. This peripheral zone is probably to be referred to the 
thickness of the umbrella mass. There is no trace of a ring canal. On the other 
hand, there is in the middle of the disk a sharply defined cross, composed of two thick 
mounds intersecting at right angles. Inthe middle of each mound runs a radial furrow 
or channel, which gradually enlarges on approaching the center. In the midfield the 
furrows of the four radial mounds, or cross-quadrants, unite to form a small, flat, 
funnel-shaped excavation. This isin any case to be referred to the gastral cavity, and 
the four crossing furrows to the four radial canals passing outward from the stomach. 
The thickness of the prominent ridges leads to the conclusion that the walls of the 
radial canals (especially toward the center of the disk) were solid and thick, perhaps 
supported by cartilage, as in many trachynemids. A conclusion as to the systematic 
position of this medusa can not be formed, on account of the very deficient impression.’ 
1 Zeitschr. fiir wiss. Zoologie, Vol. XIX, 1869, pp. 554-555. 2 Loe. cit., pp. 555-556. 
