NATURAL SCIENCES OF PHILADELPHIA. 
171 
situated more in advance than in the species just alluded to, the same sexes 
being compared. 
Log. — Indianola, Texas ; collected by John H. Clark, under Col. J. D. 
Graham. 
22. Anguilla tyrannus. — Head depressed ; anterior third of body subcylin- 
drical, somewhat deeper than wide, compressed upon the rest of the length. 
Lower jaw the longest ; gape of the mouth nearly horizontal, its angle corres- 
ponding to a vertical line drawn inwardly to the posterior rim of the orbit. 
Eye well developed and circular. Teeth small, conical, disposed upon a longi- 
tudinal band on either jaw and along the vomer also. Origin of dorsal fin 
corresponding to the exterior third of the total length ; the origin of the anal 
fin being placed somewhat anteriorly to the middle of the entire length. Scales 
narrow, elongated, cellular in structure, disposed in small groups, in which 
the longitudinal diameter of the scale assumes every possible direction. 
Log. — Mouth of the Rio Grrande del Norte (Rio Bravo) ; a specimen collected 
by John H. Clark, under Major Emory. 
VIII. NEOMURu^NA. — Neither pectoral nor ventral fins ; dorsal and anal 
low, uniting posteriorly into a point ; anterior maxillar teeth largest. One 
longitudinal series of vomerine teeth. Gill apertures lateral and subcircular. 
23. Neomur^ena nigromarginata. — Head subcorneal ; body compressed, and 
tapering into a point. Mouth deeply cleft ; jaws equal ; its gape nearly hori- 
zontal, and its angles extending considerably beyond the orbit. Origin of 
dorsal fin situated anteriorly to the branchial apertures, which are subcircular 
and rather small. The vent is placed anterior to the middle of the total 
length, where the anal fin is reduced to a mere membranous ridge. 
Log. — Collected at St. Joseph's Island, Texas, by G. Wurdemann. 
NEOCONGER. — Pectoral fins present ; dorsal and anal mostly reduced to a 
membranous ridge, uniting with the caudal where they are better developed. 
Snout tapering ; lower jaw shorter than the upper ; maxillar teeth exiguous, 
disposed upon multiple series. A patch of similar teeth on the front of 
the vomer, and one series along its median line. Gill apertures lateral, rather 
large and vertical. 
24. Neoconger mucronatus. — The head is small, slender, narrow and pointed ; 
the upper jaw protruding beyond the lower. Gape of mouth horizontal ; 
its angles extending beyond the orbits. Eyes very small, subelliptical. Vent 
situated somewhat nearer the extremity of the snout than the posterior edge 
of the caudal fin. Origin of dorsal placed a little way in advance of the vent, 
and hke the anal, it constitutes a mere membranous ridge until about an 
inch and a half from the posterior extremity of the body, where it expands, 
fin-like, and unites with the anal. 
Log. — St. Joseph's Island, Texas. Specimens collected by G. Wurdemann. 
August 24itJi. 
Vice-President Bridges in the Chair. 
Twenty-six members present. 
A paper was presented for publication in the Proceedings entitled, 
" Mineralogical Notes, by W. J. Taylor." 
Dr. Leidy made the following remarks : In the 5th volume of the Proceedings I 
have described a species of terrestrial planaria {Rhynchodemus sylvaticus,) disco- 
vered in the neighborhood of this city. This singular animal is exceedingly rare. 
I have sought for it in many localities without having found specimens. In the 
1858.] 
