676 The American Naturalist. [July, 
ter not seen in the other species of Graptemys or Malaelentmys. The 
form of the carapace is very close to Graptemys kohnii; the dermal 
shields are very thin. It is the largest form of Graptemys, the shell 
reaching a length of over 170 mm. in straight line. The color of the 
shell is light olive with yellow marks on the marginals, the plastron is 
yellow, with some darker marks. Types: No. 8808. Smithsonian 
Institution, Washington, D. C. Two not full-grown specimens, col- 
lected by Dr. T. H. Bean at Montgomery, Ala. 
The genus Malaclemys, with the single species M. centrata (Bosc. 
MSS.) Latreille, 1801, is distinguished from Graptemys by the lower 
jaw, which is pointed and not rounded in front, and also by the condi- 
tion of the quadratojugal and maxillary. In Ma/aelemys the quadra- 
tojugal is extensively united with the maxillary; in Graptemys these 
elements are separated by the quadratojugal. The peculiar character of 
the jugal in Graptemys pulehra may perhaps justify the creation of a 
new genus for this species. I have given to the common “ Diamond- 
back” the name Malaclemmys centrata (Bosc. MSS.) Latreille, 1801. 
"The name M. terrapin Schoepff, 1793, cannot be used. The same 
name (Testudo terrapen) was given by Bonnaterre in 1789 to the 
Trachemys rugosa Shaw, 1802, of Jamaica. Already in the year 1788, 
however, Gmelin introduced the name Testudo palustris for the Jamaica 
tortoise; I therefore use the name Trachemys palustris Gmelin for the 
Jamaica tortoise, and that of Malacienmys centrata (Bose. MSS.) 
‘Latreille for the “ Diamond-back.” 
KINOSTERNON LOUISIANZ spec. nov. 
Shell much like K. pensilvanicum, but more elongated. Skull differ- 
ent; the lateral hook in the middle of the maxillary very much 
- developed and very sharp; median hook on symphysis not so strong; 
postorbital arch stronger than in K. pensilvanicum. Lower jaw very 
strong, ending in a sharp point; symphysis of lower jaw larger than 
vertical diameter of orbit. A yellow-orange stripe from snout over 
"upper part of orbit along neck, one from the angle of the mouth. 
Four barbels, two just behind the symphysis near together and two 
farther behind more separated. Limbs and neck olive gray; a few 
yellow spots on top ofthe posterior part of head ; webs more developed 
than in K. pensilvanicum. Lower jaw with greyish-yellow dots and. 
lines. The whole coloration is very much like that in Aromochelys 
tristyeha Ag., which is found together with K. louisiana. seen from 
. Above these two animals resemble each other very much. They belong 
to different genera, but have about the same specific characters. 
