41 8 General Notes. [May 



several details besides in the generic characters. In the H. /mea- 

 tus the base of the posterior inner tubercle of the superior molars 

 is more distinct, and projects further inwards. The fourth pre- 

 molar is relatively larger, and the enamel is delicately plicate, re- 

 motely approaching the condition of the surface seen in Catath- 

 Iceus thabdodon. In the inferior molars, the anterior marginal 

 tubercle is wanting. The first premolar has but one root ; the 

 second and third have a posterior but no anterior basal lobe. 

 The canines of both jaws are rather large, are acute, and flat on 

 the inner side, and vertical in direction. Length of superior 

 molar series M. .032 ; of premolars, .021 ; diameters P-m. iv; an- 

 teroposterior, .005 ; transverse, .006 ; of last true molar, antero- 

 posterior, .004; transverse, .0065. Depth of ramus mandibuli at 

 M.i. .0127. 



A second species of this genus is probably the H. angnstus, 

 from the same horizon, which I described as a Mioclcenus. 



Pantolambdabathmodon, gen.et sp. nov. Founded on a man- 

 dibular ramus which supports the first true molar and the last 

 two premolars. The characters of these teeth remarkably re- 

 semble those of Coryphodon. Char. gen. Crowns of molars 

 supporting two Vs, of which the posterior wears lower than the 

 anterior. Premolars in and iv, crowns consisting of one V and a 

 short median longitudinal crest, as in Coryphodon ; 11 and 1, un- 

 known. The character which indicates that the genus is distinct 

 from Coryphodon is the elevation of the anterior branch of the an- 

 terior V of the true molar, which is more elevated than the pos- 

 terior branch. In Coryphodon it is much less elevated. The 

 type species is smaller than any known Coryphodontid. Char, 

 specif. The bases of the P-m. 111 and iv are subquadrate, the 

 inner side rounded, that of the iv relatively the wider. On the in 

 the median keel constitutes the heel ; on the iv, the keel is in the 

 center of a wide heel. No cingula. The first true molar has an an- 

 terior cingulum, but no external one. The enamel is wrinkled 

 where not worn. Diameters of P-m. in, anteroposterior, .009; 

 transverse, .007; of P-m. iv; anteroposterior, .009; transverse, 

 .0085. Width of first true molar in front, .0083. Apparently 

 about the size of a sheep. 



It will be for additional material to demonstrate whether this 

 genus belongs to the Amblypoda or Perissodactyla. It was dis- 

 covered with the preceding species by Mr. D. Baldwin in the 

 Puerco formation of N. W. New Mexico.— R D. Cope. 



"Mud Lumps" and Mounds near New Orleans. — While 

 attached to a Coast Survey party working on the Mississippi 

 river, I was informed that there were three " Indian mounds 

 back in the edge of the swamp ; on examination they proved to 

 be " mud lumps," but of a shape and material different from those 

 at the mouth of the river. I have looked over various works on 

 geology, but can find no notice of any of these elevations so far 



