Contributions to the anatomy of anthropoid apes / by Frank E. Beddard.
- Frank Evers Beddard
- Date:
- 1893
Licence: Public Domain Mark
Credit: Contributions to the anatomy of anthropoid apes / by Frank E. Beddard. Source: Wellcome Collection.
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![ancestrula. Fig. 2. Part of zoarium from Bracklesham (B 4339), showing the front wall partly broken away. Fig. 3. Part of a worn specimen from Bracklesham, resembling- L. urceolata. Affinities. This species belongs to the L. radiata, Lamk., group, which the Marquis de Gregorio [No. i, p. 248] has recently proposed to make into a new subgenus, Demi- clausa; this, however, is against all rules, as L. radiata is clearly the type species of the genus. If, therefore, the separation is to be made, it is the other group that must be renamed and removed. Demiclausa is an absolute synonym of Lunulites. This species was figured by Lonsdale as Lunulites urceolata, Lamk., but from the latter it widely differs in the fact that the vibracularia are connected by depressions into long radial lines; in L. urceolata they are disconnected. From Lunulites radiata, Lamk., this differs by the gradual transition from the vibra- cularia to the normal zocecia, and by the presence of a lamina and tubercles on the rim of the opesia. The species agrees most closely with L. subplana, Reuss [No. 3, p. 264, pi. xi. fig. 108], but the apertures in that species are not clithridiate, nor does there seem to be a gradual transition from vibracularia to zocecia. It clearly differs from Lunulites quadrata, Reuss [Cellepore quadrata, Reuss, No. 1, p. 95, pi. xi. fig. IT; in the explanation of the better figure given in Reuss, No. 11, pi. xxviii. fig. 18, the species is called Lepralia tetragona], by the form of the aperture and the absence of the raised rim immediately around it. The original figure gives a suggestion of a similar passage from vibracularia to normal zocecia. In the main character of this species it resembles Lunulites goldfussi. Hag. [No. 2, p. 102, pi. xii. fig. 5], but that differs by the irregular distribution of the vibracularia. Genus Biselenakia, nov. nom. Syn. Diplotaxis, Reuss, 1867, non Kirby, 1837, Ueber Bry. deut. Unteroligocans, Sitz. k. Ak. Wiss. Wien, Bd. lv. Abtb. i. p. 231. Diagnosis. A Membraniporid with a bilaminate zoarium, which is small and circular and discoid in form ; typically the form is bun-shaped. The zocecia of the upper layer have regular Membraniporidan apertures, with numerous normal vibracularia irregularly scattered, or one to each zocecium. The zooecia of the lower surface are much modified ; the aperture is contracted by the great thickening of the peristome ; in the zooecia near the centre the aperture is sometimes completely closed or persists as a long narrow slit; the vibracularia are similarly modified ; some of the peripheral zooecia more nearly resemble those of the upper layer. Type species. Biselenaria placentufa (Reuss), op. cit. Remarks cn the Genus and its Affinities.—Reuss practically founded his genus Diplo- taxis simply on the one character of its bilaminate zoarium; the species included in it are forms of much interest, and there seems to be no reason to question the validity](https://iiif.wellcomecollection.org/image/b28141386_0082.jp2/full/800%2C/0/default.jpg)
