SUBJECT INDEX — MORPHOLOGICAL SECTION 



397 



Pacific Ocean 



Off Japan. Jordan, D. S. 1898.2; 

 Jordan, D. S. & Snyder, J. O. 1903.1; 

 •Jordan, D. S. & Starks, E. C. 1904.1 

 {List); Tanaka, S. 1910.1. 



Southern Pacific. Gilbert, C. H. 1908.1, 

 1911.1. — Hawaiian Is. -A-Gilbert, C. 

 H. 1905.1. —Off Tasmania. McCuUoch, 

 A. R. 1907.1. —Off New Zealand. Ham- 

 ilton, A. Add. 1896.1. 



DENTITION (OP FISHES) 



Comprising the development, histology, 

 and morphology of the teeth of fishes. 



For related subjects, see Integument, and 

 Dermal Skeleton. 



General treatises 



Works of a general nature, chiefly 

 comparative odontologies or manuals of 

 the dentition of all vertebrates, including 

 chapters on fishes. 



Text in English. •Owen, R. 1840.1; 

 Wortman, J. L. 1886.1; •Tomes, C. S. 

 Add. 1914.1. 



Text in German. Baume, R. 1882.1; 

 Giebel, C. G. 1855.1; •Terra, P. Add. 

 1911.1. 



An excellent short non-technical account 

 in English on the teeth of fishes, is •Ride- 

 wood, W. G. 1896.2. 



Probably the most scholarly treatises in 

 German are those died under •Rose, C. 

 1892.1-1896.1, 1897.1. 



Miscellaneous topics 



Homology of hair with teeth of shark. 

 Brandt, A. T. 1898.2. 



Origin of perforations in teeth of a fossil 

 Carcharodon. Burrows, H. A. 1876.1. 



Suppression and specialization of teeth. 

 Humphreys, J. 1889.1. 



Fishes' teeth contrasted with those of 

 other classes. Menhuir, W. H. 1902.1. 



Nerve terminations in teeth of Teleostei. 

 Retzius, M. G. 1892.9. 



Structure and anchorage in vertebrates. 

 Struck, W. 1915.1 ; Watson, G. W. 1900.1. 



Origin of teeth 



The identity in development and structure 

 of the placovd dermal elements (shagreen 

 denticles) with the teeth, in Elasmobranchs, 

 was recognized in Williamson, W. C. 

 1849.1, and elaborated in •Hertwig, O. 

 1874.1. 



During the inpushing of the outer skin 

 in the formation of the stomodseum, these 

 placoid elements (teeth) have been car- 

 ried into the oral cavity. While teeth are 

 generally restricted to supporting bones 

 or cartilages, in numerous species of 

 sharks and rays, practically unmodified 

 placoid scales persist in the lining of the 

 oral cavity and pharynx. 



For references, see Imms, A. D. 1905.1; 

 Spengel, J. W. 1905.1; •Steinhard, O. 

 1903.1. 



Similar oral and pharyngeal denticles in 

 Chimmroids are figured in Dean, B. 1906.1, 

 p. 121. 



The formation of a triconodont tooth (%n 

 Chlamydoselachus) , through the fusion of 



three separate simple teeth, is shown in 

 •Rose, C. 1894.2. 



Histology of teeth 

 Histological structure and development of 

 teeth. Born, G. 1827.1; Fischer von 

 Waldheim, G. ISOl.l; Heincke, ]?. 1873.1; 

 Hilgendorf, F. M. 1888.1; Morgenstern, 

 M. 1909.1; Owen, R. 1839.4, 1840.3; 

 •Rose, 0. 1897.1; Schwalbe, G. A. 

 1894.1; Waldeyer, H. W. 1864.1; Hux- 

 ley, T. H. Add. 1853.1; Owen, R. Add. 

 1S39.1. 



enamel- 

 As early as 1848, M'Coy (Sir F. 1848.1, 

 p. 124) following the then recognized fact that 

 the enamel of fishes differs in development from 

 that of mammals, applied the term " ganoine " 

 to the layer of " false enamel " on the teeth of 

 certain fossil sharks (Chomatodus). As pointed 

 out to him by Prof. Owen (Owen, R. 1849.1) 

 the latter's term " vitrodentine " had previously 

 been in use. About the same time, Williamson 

 (W. C. 1849.1, p. 438) independently, but more 

 aptly, used the term " ganoin " for the enamel- 

 like substance of the scales of Lepidosteus. 



While the exact nature of enamel seems not 

 yet entirely settled, a recent authority (Tomes, 

 C. S. 1900.1, p. 62) retains the term " enamel " 

 which he divides into the following types. 



(1) Enamels not wholly epiblastic in origin. 

 The stroma which is the seat of enamel calci- 

 fication is furnished by a transformation of the 

 exterior of the mesohlastic dentine papilla, the 

 ameloblasts apparently segregating the lime 

 salts lequired for its hardening. (This type 

 is found in Elasmobranchs and is imquestion- 

 ably a modified dentine — vitrodentine of 

 Owen.) 



(2) Enamels wholly epiblastic in origin, in 

 which the ameloblasts undergo a prior trans- 

 formation into a stroma of the dimensions of 

 the finished enamel and themselves disappear. 

 This type is met with in the Gadidse, in Sargus 

 and in Labrus and probably other fishes. 



(3 and 4) The other types, also epiblastic in 

 origin but in which the ameloblasts persist, are 

 confined to the mammals. 



For papers specifically relating to de- 

 velopment and structure of enamel, see 

 Nunn, E. 1883.1, and •Tomes, C. S. 

 1898.1-1900.1. 



DENTINE 



Although accurately described as early as 

 1836 by Retzius (A. J. 1836.1), the various 

 forms of dentine were not named until the ap- 

 pearance of the " Odontography " of Owen 

 (Owen, R. 1840.1) whose terms are now gen- 

 erally accepted. 



As more precisely defined by Tomes (C. S. 

 1878.2), the forms now recognized are (1) hard 

 unvascular dentine, (2) vaso-dentine, (3) plici- 

 dentine (Labyrinthodon, not in fishes), and 

 (4) osteo-dentine. 



Structure and development of dentine. 

 Korff, K. 1910.1; •Mummery, J. H. 

 1893.1; Studnieka, F. K. 1906.2, 1909.2; 

 Sternfeld, B. Add. 1882.1; •Tomes, 0. 

 S. 1878.2. 



Cornified epithelial teeth of 

 Cyclostomata 



In this group the teeth are purely cuticular, 

 formed by an axial dermal papilla, invested by 

 epidermis and an external horny cone. They 

 are without genetical relations to the teeth in 

 other groups. 



In Myxine and Bdellostoma, according to 

 Beard, the dermal papilla develops an_ imper- 

 fectly calcified tooth beneath the epidermal 

 cornification. 



