IGUANIDA, —CXVI. 203 
298. HOLBROOKIA Girard. (To Dr. John Edwards Holbrook, 
of Charleston, author of ‘ North American Herpetology,” etc.) 
591. H. maculata Girard. Gray, paler above, with a row of 
large darker spots on sides; 1 or 2 black spots on side of belly; 
scales nearly smooth; hind leg not reaching eye. S. W. (extra- 
limital). 
299, SCELOPORUS Wiegmann. (oxédos, leg; mépos, pore.) 
592. S. undulatus (Daudin). Common Lizarp. Swirt. 
Greenish, bluish, or bronzed, with black, wavy cross-bands above; 
throat and sides of belly in ¢ with brilliant blue and black; dorsal 
scales rather large, strongly keeled, mucronate similar to lateral 
scales; head shields striated or rugose ; body depressed ; tail slender. 
L.7. U.S., in forests and along fences, N. to Mich.; abundant 
S.; varies greatly in color. 
300. PHRYNOSOMA Wiegmann, (pivos, toad; capa, body.) 
593. P. brevirostre (Gir.), Ventral scales smooth. Head spines 
small, shorter than eye ; grayish, with large, dark, pale-edged spots. 
S. W. 
594. P. cornutum (Harlan). Common Hornep Toap. Ven- 
tral scales keeled; head with very long spines; back with spinous 
scales; gray, with pale dorsal streak and some dark spots. L. 5. 
N. M. to Cal. and S.; common S. W. ; a most grotesque little crea- 
ture; terrestrial. (Lat., horned.) 
Orper XXX. TESTUDINATA. (THE TuRrTLEs.) 
Reptiles with the body enclosed between 2 more or less developed 
bony shields, which are usually covered by horny epidermal plates, 
but sometimes by a leathery skin. Upper shield (carapace) 
and lower shield (plastron) more or less united along the sides. 
Neck and tail the only flexible parts of the spinal column; these, 
together with the legs, usually retractile within the box made by 
the two shields. The bony part of the carapace is formed by the 
dorsal and sacral vertebra, and the ribs co-ossified with a series of 
overlying bony plates, usually accompanied by a marginal row. 
The dorsal vertebre have their ends flattened and immovably 
united by cartilage, and all of them, except the first and last, have 
their neural spines flattened horizontally so as to form the median 
line of plates. On either side of this series is a single row of ossi- 
fied dermal plates overlying the ribs and corresponding in number 
to the developed ribs, of which there are usually 8 pairs. No true 
sternum; plastron consisting of membrane bones, of which there 
are usually 9 pieces,—4 pairs and a single symmetrical median 
