NATURAL SCIENCES OF PHILADELPHIA. 113 



has measured about eight lines, the transverse diameter about three-fourth- of 

 an inch. 



Prof. Leidy further stated that in a recent visit to the Schuylkill river at 

 Fairmount, to seek for specimens of Urnalella, though he had been ansae) i 

 ful in obtaining living ones within reach from the shore, lie had found in the 

 same positions occupied by the former, an abundance of Cordylophora. This 

 is the first time that he had noticed this interesting compound hydroid polyp 

 in the vicinity of Philadelphia, and be -was surprised that until now it had 

 escaped his notice. Cordylophora was first detected by him in this country at 

 Newport, R. I. He had not been able to satisfy himself that it was a different 

 species from the European Cordylophora lacustris, first described by Prof. All- 

 man of Edinburgh. It appears, however, to be much smaller. Prof. Allman 

 represents the C. lacustris several inches in length, with the polyps a line in 

 length. Oars is not more than half the size. As a variety it might be named 

 Cordylophora americana. 



Oct. 25th 

 The President, Dr. Kuschenberger, in the Chair. 



Twenty-four members present. 



Prof. Leidy stated that he had recently received from Prof. Hayden, at the 

 latest date, at Fort Bridger, several boxes of fossils, most of them remains of 

 Crocodiles and Turtles from Church Buttes, the junction of the Big Sandy and 

 Green Rivers, &c. Of these he proposed to give a notice at another period. 

 Among the mammalian remains there were some of special interest, and to 

 these he wished to direct attention at the present time. The first exhibited 

 consisted of the crowns of teeth and fragments of others, of a pachydermous 

 animal, approaching in size the common Ox. Thecrown of a lower true molar 

 resembles in its constitution those of Palxotherium, Chalicotherium and Tita- 

 notherium, being composed of a pair of fore and aft conjoined pyramidal lobes 

 with crescentic summits. It measures 16 lines antero-posteriorly and 10 lines 

 transversely. Fragments of upper true molars exhibit the outer part of the 

 crown composed of a pair of lobes exactly as in Hyopotamus. The inner 

 portion of the crown is composed of a pair of simple cones, broad and low, 

 the front one considerably larger than the back one. One of the specimens 

 in the entire condition of the crown measured about 22 lines fore and aft 

 and 18 lines transversely. The crown of an upper premolar lias its outer 

 part composed of a pair 'of conjoined cones with acute summits and sides. 

 The inner portion of the crown consists of a single broad simple cone em- 

 braced in front and behind by a basal ridge. The anteroposterior diameter 

 of the crown externally measures 9k lines ; the transverse diameter is an 

 inch. 



The teeth indicate an animal apparently allied to Chalicotherium and Pitano- 

 therium, but different from either. The name of Pa^osyops palttdosos was 

 proposed for it. The remains were obtained at Church Buttes. and belong, 

 as Prof. Hayden reports, to the tertiary formation of the Bridger Group. 



Another fossil exhibited was discovered by Prof. Hayden at Black's Fork. 



It consists of a fragment of the lower jaw, containing two teeth, ot an ani- 

 mal about as big as a Rabbit. The teeth, consisting of the two last molars, 

 resemble in their construction those of the Peccary, but the constituent lobes 

 of the crown are more pointed and smoother. The second true molar has four 

 lobes ; the last, an additional lobe. The two teeth together occupy a space of 

 less than 5 lines; the depth of the jaw beneath the penultimate molar , 8 three 

 lines. For the animal, the name of Microsus cuspidatus was proposed. 



Another fossil consists of the greater part of the right ramus > of a lower jaw 

 partially imbedded in sandstone, and was also obtained by I rot. Hayden at 



1870.] 



