Diversity in the Scutes of Chelonia. 



11 



(See also "abbreviations," below.) The nuchal is not, for present purposes, 

 included in the neural series. As the term "intergular" is commonly applied 

 both to the unpaired scutes, anterior to the gulars (typical of certain species) 

 and also to a smaller or larger median scute at the posterior-median angles 

 of the gulars (of other species), I will use the name intergular only in the 

 former sense, for a median scute on the anterior margin between the gulars 

 (Fig. C) ; interplastral is applied to other median shields of the plastron 

 (Fig. B). The terms "inframarginal" and "submarginal" must be distin- 

 guished. Infrmnarginal applies to a series of scutes separating pectoral and 

 abdominal shields from the marginal series (a typical series in Chcloniidae, 

 etc. (Fig. C), and, presumably, represented in other species by the axillaries 

 and -Uu/iiiiKih) (Fig. B) ; siihmarginal is used, as applied by Baur COO), to 

 anomalous scutes found between the inframarginals and marginals (Fig. C). 



Interjular 



Infra - 

 -'/ Marginals 



Sub- 



,' Mar|inals 



;, Marginals 



Fig. C. Plastron of a specimen of Thalassochelys caretta (L.). Note the 

 anterior unpaired intergular, the series of inframarginals, and the small 

 anomalous suhmarginals. 



It seems impossible to escape the use of words that could be taken 

 to imply more than is intended. It may, for instance, be perfectly 

 normal for one turtle to have a scute not possessed by most of its 

 fellows of the same species, but, for our present purpose, the number 

 and arrangement typical of the species is termed "normal." A scute 

 not found in the typical plan will be described as an "abnormality," 

 an "anomaly," a "supernumerary" scute, or a "variation." The 

 collective term least liable to mislead is "diversity," and this is used 

 whenever practicable. 



