7O H. H. NEWMAN. 



rows of plates, a single median and two paired rows. The median 

 row has been variously designated as dorsal, vertebral and neural. 

 In this paper the term neural will be invariably used. The neural 

 row consists of the following elements : an anterior plate of large 

 size called the nuchal (;/?/.), eight neurals (n. i-S), two procaudals 

 (pr. I and 2), and posteriorly the pygal (/>.). 



Lateral to the median row are the paired costals (c. I 8), 

 directly overlying the eight pairs of ribs. 



Bordering the carapace on both sides and extending from 

 nuchal to pygal are the marginals (;//. i 1 1). 



The plates of the plastron (Fig. 2) are nine in number the 

 paired epi- (V.), hyo- (ho.}, hypo- (hp.}, and xiphi- (.r.) plastrals, 

 and the unpaired endo-plastral (en.}. 



The hyo- and hypoplastrals articulate directly with the fourth, 

 fifth and sixth marginals and form the so-called " bridge ' be- 

 tween the dorsal and ventral armor. 



B. Scutes. - - On the carapace (Fig. i) there are, as in the case 

 of the plates, five longitudinal rows of scutes that receive the 

 same names as the plates. The median row, neurals, consists 

 of a small anterior element, the nuchal (NU.}, and five large 

 neurals (N. 1-5). There are four pairs of large costals (C. 1-4). 

 Twelve pairs of marginals (M. 1 12) completely surround 

 the carapace with the exception of the small space occupied by 

 the nuchal. 



The scutes of the plastron (Fig. 2) are twelve in number, con- 

 sisting of six pairs of large flat elements named from anterior to 

 posterior end as follows : gulars (6".), numerals (H.}, pectorals 

 (P.}, abdominals (A.}, femorals (F}, and anals (AN}. 



At the angles made by the junction of the pectorals and ab- 

 dominals with the marginals are two pairs of small triangular 

 scutes called respectively axillaries (A^.) and inguinals (/.). These 

 constitute all that remains in the Emydidae of the inframarginals, 

 a row much more prominent and complete in more primitive 

 families. 



No other plates or scutes occur normally among the Emydidae, 

 but for the sake of completing the nomenclature, it should be 

 mentioned that one species, Macrochelys teunnincki, possesses an 

 additional pair of rows of scutes between costals and marginals, 



