96 FOSSIL MEDUS 2. 
the Rhizostome. The figures in the plate show quite clearly the general 
form of the parts described by Dr. Pohlig, and I have received, through the 
courtesy of Dr. Wilhelm Pabst, of the Herzogliches Museum at Gotha, a 
photograph of a slab containing a number of impressions of the same char- 
acter. Dr. Pabst also calls my attention to a photograph of a slab from the 
Upper Rothliegende of Thiiringen, from Tambach in the Duchy of Gotha, 
containing some impressions which Dr. H. Potonié has designated Spongi- 
nopsis dyadika 
A specimen of this species kindly supplied for study by Dr. Pabst 
shows a smooth outer zone and a confused, apparently lobate central por- 
tion. The peripheral boundary of this speci- 
men is quite distinctly double. 
MEDUSINA ? sp. undet. 
Through the courtesy of Dr. H. B. Geinitz, 
T have received a cast of a form that has been 
tentatively referred by him to Medusites. It 
occurs in the Bunter Sandstein of the Upper 
Trias near Grotenleite (or Crotenleeide), be- 
tween Géssnitz and Meerane. The cast indi- 
Fig. 24.—Restoration of Medusina atava. Cates an impression such as might be made 
aaa by the body of a medusa, but, as Dr. Geinitz 
says in his letter, the remains are too indistinct to warrant any definite 
statement regarding them, except that they show some resemblance to 
forms like ‘‘ Medusites lindstrémi.” 
INCERT SEDIS. 
It is possible that imprints or casts.of fossil medusze have been described 
and figured by authors who have not recognized their true characters. Two 
have come to my notice, to which I wish to call attention as being worthy 
of further investigation. One of them is described and illustrated by Dr. 
H. A. Nicholson as Buthotrephis (?) radiata. It is a peculiar radiate fossil 
from the Skiddaw slates (Ordovician), that suggests the imprint of a medusa; 
and it seems desirable to have the specimens studied from this point of view. 
The figures ' recall the appearance of some of the medusz and trails on the 
!On the occurrence of plants in the Skiddaw slates: Geol. Mag., Vol. VI, 1869, Pl. XVIII, 
figs. A, B, and D. 
