. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. Natural history. 162 Annals of the South African Museum. which siirround a single bone undivided by any median suture. Sutures are not traceable in the parietal boss ; but a short distance behind it a median suture between the two parietals is visible. The evidence thus points strongly to the conclusion that there is a single median bone between the frontals and the parietals, forming at least part of the boss around the pineal foramen. In the type of Eocyclops longus there is no doubt that a median suture occurs just
. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. Natural history. 162 Annals of the South African Museum. which siirround a single bone undivided by any median suture. Sutures are not traceable in the parietal boss ; but a short distance behind it a median suture between the two parietals is visible. The evidence thus points strongly to the conclusion that there is a single median bone between the frontals and the parietals, forming at least part of the boss around the pineal foramen. In the type of Eocyclops longus there is no doubt that a median suture occurs just in front of the pineal foramen ; and the question again arises therefore—How much stress can be laid upon the presence or absence of the pre- pai'ietal ? It is just possible, of course, that in the South African Museum specimen the suture in front of the foramen between two. FIG. 40.—Eocyclops longus, Br. Skull. No. 3425. x $ nearly. parietals may have been obliterated; but the other sutures on the skull stand out so clearly, and that between the parietals in their posterior part is so obvious, that this does not seem a feasible solution of the matter. It would seem much better to suppose that, although in the smaller Dicynodonts the preparietal is a constant within any one species and is constantly present or absent in the genus, in the case of these very large—and presumably somewhat aberrant—forms the bone is inconstant in character and is not of importance sys- tematically. Certainly the three skulls— Mus. 3425, type of •" Oudenodon magnus " and type of Eocyclops lonyus—agree so closely in other regards, as far as can be seen from the somewhat incomplete descriptions, that this one difference can scarcely be held to be sufficient to separate them generically. The skull from Graaff Reinet is in very fine condition and is worthy. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabil
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