176 
Miscellaneous. 
arranged in a nearly flat ring, as in Ichthyosaurus, but form the 
basal segment of an elongated cone, as in the eyes of some birds. 
The vertebras are short and deeply biconcave. The neural arch is 
articulated to the centrum. One trunk-vertebra measures 85 
millims. in width, 38 millims. in length on the floor of the neural 
canal, and 21 millims. between the centres of the two rib-articular 
faces of the same side. The length of the entire animal was about 
8 or 9 feet. The remains at present known are all in the museum 
of Yale College. 
This reptile may be called Sauranodon natans , and the order it 
represents Sauranodonta. This genus bears a similar relation to 
the Ichthyosaurs that Pteranodon does to the true Pterodactyls ; and 
it is interesting to find the two highly specialized forms preserved 
in the same region. 
The geological horizon of the Sauranodontidse, so far as now 
known, is in the Jurassic, immediately below tbe Atlantosaurus- 
beds. The accompanying fossils are Ammonites and Belemnites, 
showing more distinctly marine deposits, which may be called the 
Sauranodon-beds. — Araer. Journ. Sci. 4' Arts, January 1879. 
Yale College, New Haven, Dec. 27, 1878. 
Notice of a Tetrarhynchus. 
Prof. Leidy stated that in the Remora , or Sucker, from our coast, 
presented this evening by Mr. Holbrook, he had found a curious 
parasite. This was enclosed in a compressed oval cyst, pearly 
white, thick-walled, and about half an inch long, tightly adherent 
to the intestine of the fish. The cyst contained a flask-shaped 
translucent whitish sac, which was feebly contractile, and furnished 
at the narrow end with two minute papillae, which were slowly 
protruded and retracted. Within this sac-worm, coiled tip about 
the centre, was an opaque white worm or scolex, which proved to 
be a Tetrarhynchus. Removed and extended it measured 7 lines 
long, and was divisible about equally into a broad anterior body 
portion, and a posterior narrow tail-like portion. The head was 
formed of a pair of obcordate bothria inclined from each other. 
Four long tortuous proboscides extended through the body and 
projected from the head. The projecting portions were successively 
elongated and shortened by eversion and inversion, and were armed 
with recurved hooks. The hooks extended within half the length 
of the proboscides, and, as they were everted and inverted, appeared 
like the streaming of liquid through narrow tubes. The tortuous 
proboscides at the bottom were continuous with as many elliptical 
pedestals placed at the back part of the body. The tail, about half 
the width of the body, was not segmented, but exhibited a disposi¬ 
tion to assume this condition. The end was slightly tapering, and 
occupied by a bell-shaped sinus, opening externally, and alternately 
contracting and expanding. The interior of the sinus was lined, 
and its mouth thickly furnished with non-vibratile cilia. The 
species appeared to be undescribed, and was named Tetrarhynchus 
tenuicaudatus. — Proc. Acad. Nat. Sci. Philad. Oct. 15, 1878. 
