NATURAL SCIENCES OF PHILADELPHIA. 211 



FISHES. 



Philypnus dormitator, C. V. 

 Tetragonopterus streetsii, Cope, sp. nov. 

 Xiphophorus hellerii, Heck. 

 Fundulus, sp. 1. 

 Fundulus, sp. 2. 



HYDROPS LTJBRICUS, Cope, sp. nov. 



Head short, broad, little distinct from neck. Scales entirely 

 smooth, poreless. Posterior grooved tooth not much larger than 

 those in fi-ont of it. Head-shields normal, labials not divided ; 

 loreal distinct, not reaching orbit; oculars 1-2. 



Internasals contracted in front. Frontal wide, with parallel 

 sides longer than muzzle in front of it. Parietals still longer, 

 somewhat contracted behind. Rostral broad, low ; loreal small, 

 higher than long. Temporals 1-2, first in contact with two labials. 

 Superior labials eight, fourth and fifth bounding rather small 

 orbit; seventh wider above than below. Inferior labials 10 or 11, 

 4.5 in contact with anterior, 1.5 with posterior or longer genials. 

 Scales in 21 rows. Anal divided. Tail 4| times in total length. 



Ground color above, a stone brown. A blackish lateral band 

 extends from the end of the muzzle to the end of the tail, includ- 

 ing all between the approximated edges of the second and sixth 

 rows of scales. A dark brown shade extends throughout the 

 length on the vertebral, and two series of scales on each side of 

 it. Below the second row of scales white (? in life j-ellow), a 

 large black spot marking the third from each end of each gas- 

 trostege and urostege, thus forming two series. Labial plates 

 above and below, pale with a black spot ; gulars and geneials 

 similar. Total length two feet. Gastrosteges 162. TJrosteges 71. 



This species was found by Dr. T. H. Streets on the bank of the 

 Coatzacoalcos River, in the department of Vera Cruz, Mexico. It 

 is excessively smooth, so much so as to produce the sensation of 

 an oiled surface when the finger is passed over the scales. 



TETRAGONOPTERUS STREETSII, Cope, sp. nov. 



Radii D. 11, A. 25 ; scales 1-41-5. Maxillary bone elongated, 

 the extremity extending to below the anterior part of the pupil, 

 its margin toothless. Profile nearly plane, rising into the convex 

 dorsum at the supra-occipital crest; muzzle obtuse, jaws nearly 



1871.], PART II. — 15 



