JURASSIC. és 73 
Family HFKULITHOTID Haeckel. 
Genus EULITHOTA Haeckel. 
EULITHOTA FASCICULATA Haeckel. 
Pl. XLY, figs. 3, 4. 
Bulithota fasciculata Haeckel, 1869. Zeitschr. fiir wiss. Zoologie, Vol. XIX, pp. 
549-553, 559, Pl. XLII, figs. 1, 2. 
Bulithota fasciculata Haeckel, 1880. System der Medusen, p. 647. 
Bulithota fasciculata Ammon, 1886. Abhandl. Math.-phys. Classe Kénigl. bayerischen 
Akad. Wiss., Vol. XV, p. 157. 
Dr. Haeckel’s descriptive remarks are essentially as follows:' 
‘The impression of this medusa shows the animal lying on its oral side, and the 
depth and distinctness of its outline bear witness to the considerable cartilaginous 
consistency of the gelatinous mass. By a careful inspection it is shown that the 
peripheral outline of the disk takes on almost the form of a regular octagon, while at 
equal intervals lie eight pit-like depressions of an irregular form, directed radially. 
These eight marginal pits have evidently been produced by some especially thick and 
firm portion of the body rim, and probably by those well-known sense organs distin- 
guished by the name of ‘“‘rand-koerper” (marginal bodies), while the filaments stream- 
ing out from them were probably formed by marginal tentacles. It is necessary to 
believe that the latter belong to the hard and fast category of marginal tentacles 
whose axis is supported by a central cartilaginous band, for tentacles of the other 
class, which represent a thin-walled, hollow cylinder, could hardly, under the most 
favorable circumstances, leave behind so sharp and distinet an impression. There is 
in favor of this hypothesis the somewhat hard and stiff position of the tentacles of 
our fossil, which is exactly as in the cartilage tentacles described by me. The 
umbrella rim of our Eulithota appears to be supplied with tentacles only at the eight 
prominent places where are the hollows of the ‘‘rand-koerper,” or sense organs, and, 
in fact, they form a tuft which was probably fastened immediately beneath the base 
of the sense organ. Only four tentacles can be clearly and unquestionably made out 
in each bunch, but probably their number was much more considerable. 
Arising from the octagonal periphery of the disk rim are 16 equal crescent- 
shaped depressions, directed inward, and terminating outwardly in a smooth, sharply 
detined convex curye. These can be nothing else than the 16 lobes of the deeply 
indented umbrella rim. That they project convexly inward instead of outward is 
easily explained by supposing that the disk of our medusa (as in many still living 
forms) had its greatest diameter, not at the disk margin at the mouth of the umbrella 
cavity, but some distance above the rim. Accordingly, the umbrella cavity must 
have been wider above its orifice than at it. The indentation between any two mar- 
ginal lobes is very deep. ; 
Centrally from the infolded lobes of the disk rim there follows, in our impression, 
a rather strongly prominent ring which presents no especial structural features. It 
' Zeitschr. fiir wiss. Zoologie, Vol. XIX, 1869, pp. 549-552. 
