Plagiostomata of the Pacific. Pt. I. Fam. Heterodontidae / by N. de Miklouho-Maclay and William Macleay.
- Nicholas Miklouho-Maclay
- Date:
- [1878]
Licence: Public Domain Mark
Credit: Plagiostomata of the Pacific. Pt. I. Fam. Heterodontidae / by N. de Miklouho-Maclay and William Macleay. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![I have already mentioned that the chief peculiarity of the den- tition of H. galeatus is the longitudinal ridge on the posterior teeth ; which character, if found in fossil Plagiostomous teeth, would very probably have induced Agassiz to describe them as belonging to a new genus. If disregarding the anterior (tri- cuspidate) and the middle (multi-cuspidate) teeth, and regarding only the posterior (elongated and ridged), we compare the latter with the fossil Plagiostome teeth (or to speak more correctly, with the Pig of the Atlas of the Poisson fossiles of L. Agassiz) we find (on plate 12 of the 3rd vol. of the Atlas) several figures which have very much the appearance of the lateral teeth of H. galeatus. These are the different teeth of Psammodus linearis, Agass. I must, however, add that this resemblance struck me more from looking at the illustrations (figs. 9—13) than from reading the text (Tome III., p. 107 and 108.) I believe, however, that one would be only entitled to come to a decisive conclusion after examining the fossils themselves and not merely the drawings of them. 4.—Dentition of Heterodontus Prancisi. Girard. After I had carefully examined the form of the teeth of H. Pliillipi and H. galeatus, it was very interesting to me also to investigate those of H. Francisi. Unfortunately, there was at my service only one specimen, which, as a “Museum specimen,” I could examine only from without. The anterior teeth were perfectly visible, and could be sketched without in- terfering with the specimen. It was otherwise with the impor- tant posterior teeth, to see which, in detail, a lateral incision of a few inches, from the margin of the gape into the cheeks would have proved very useful. I was obliged, however, to content myself with looking in through the aperture of the mouth, so that the sketching of the posterior teeth was rendered a matter of great difficulty. I succeeded, however, in making the accom- panying sketch (fig. 37). The form of the teeth in H. Francisi resembles, on the whole, that of a young H. Phillipi; the front teeth were tri-cuspidate. In the posterior rows of large teeth there were no teeth so large as are found in many adult [22]](https://iiif.wellcomecollection.org/image/b22367913_0024.jp2/full/800%2C/0/default.jpg)
