1894.] Recent Literature. 789 
dyle is caducous, as it is in the Diadectidx, and has been lost from the 
specimens Dr. Seely has examined. It is this peculiarity that led me 
into error in my first diagnosis of the Cotylosauria. 
Prof. Seeley makes quite full comparisons with the forms of the 
American Permian. ,He seems impressed with reptilian affinities in 
Eryops. But this genus is a true Stegocephal in every respect, and 
has no greater affinity with the Cotylosauria than any other member of 
the order. In quoting my description of the tarsus of the Clepsydro- 
pide, he falls into error in stating that I allege that “the tibials and 
centrals united to form an astragalus." I have stated that the inter- 
medium and centrals unite to form the astragalus. He also states that 
I have not figured the intercentra of the Pelycosauria. He will find 
that my figures of Clepsydrops and Dimetrodon represent them. 
Dr. Seeley shows that the structure of the vertebral column and pel- 
vic arch have a close similarity in the Cotylosauria, Anomodontia and 
Theriodonta of South Africa. I have discovered the same characters 
of these regions in the Cotylosauria and Pelycosauria of North Amer- 
ica. For the order which is to include these divisions, Seeley, like 
Lydekker, retains the name of Anomodontia of Owen. But Owen 
originally proposed this name for the group which includes the genera 
Oudenodon, Dicynodon and Lystrosaurus (Ptychognathus Owen). Fur- 
ther, in his work of 1876* on these reptiles, he continued this use of 
the name, making it of equal rank with the Theriodonta. It being 
evident that the entire division required a name, I gaveit that of Thero- 
morpha (Proceed. Amer. Philosoph. Soc., 1880, p. 38); (subsequently 
altered to Theromora, on account of preoccupation.) The use of the 
name Anomodontia for this order has no support in the rules of nomen- 
clature. 
Dr. Seeley discusses the possible relation of the Pelycosauria of the 
American beds with the African Theriodonta. There are important 
resemblances between these groups. Unfortunately, corresponding 
parts of the two are in several cases unknown. Thus the shoulder 
girdle and tarsus of the Theriodonta have not been yet obtained. Un- 
til these lacun: are made good we cannot determine the mutual affin- 
ities of the two. We naturally look to Prof. Seeley for more light on 
this subject. It is possible, also, as I have suggested, that the postor- 
bital arch of the Theriodonta is the superior arch (supratemporal), 
and not the inferior arch (zygomatic), as in the Pelycosauria. 
NoTE.—In my paper on the Plesiosaurian skull (Proceeds. Amer. Philos. 
Soc., 1894, p. 111, line 10), by a lapsus calami, I wrote Proterosauria for 
* Description of the Fossil Reptilia of South Africa in the British Museum. 
