A study of the structure of Lingula (glottidia) pyramidata Stim. (Dall) / by H.G. Beyer.

  • Beyer, Henry Gustav, 1850-1918.
Date:
[1884]
Catalogue details

Licence: Public Domain Mark

Credit: A study of the structure of Lingula (glottidia) pyramidata Stim. (Dall) / by H.G. Beyer. 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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    Wm. H. Dall, of the Smithsonian Inst., and the following account is a description of the genus in his own words: Glottidia jpyramidata (Stm.) Dall. This hrachiopod was originally described by Dr.Wm. Stimp- 8on under the name of Lingula pyramidata {Am. Journ. Sci. & Arts, XXXIX, p. 444,1860), and was obtained by him in North Carolina.1 In 1870, while engaged in the study of the Lingulas in the National Collection, I discovered that some species were dis- tinctly separated from the typical form of the genus, in being provided with raised fulcra for the attachment of certain muscles, forming a median septum in one and two divaricating septa in the other valve. To this group I applied the name of Glottidia, which has been adopted. The type is a species very similar to southern specimens of G. jpyramidata—namely, the G. albida of Hinds. There are three other closely related forms on the west coast of America; G. semen Brod., G. audebarti Brod. and G. Palmeri Dall. On the eastern shore of America, besides G. jpyr- amidata there is another, G. antillarum Heeve, described in the Conchologia Iconica in November, 1859, from a single specimen, now in the the British Museum. It is not improbable that the latter will prove to be iden- tical, when a sufficient number of specimens are collected for study, with G. jpyramidata; in which case Eeeve's name has priority. All these species of Glottidia are probably descended from the same source or ancestral form, and no species have yet been found except in American waters, while on the other hand not a single species of the genus Lingula, in the strict sense, is known to occur in America, though all the Glottidiae were origi- nally described as Lingulae. The true Lingulas are almost al- ways attached to a fixed rock or stone, while Glottidia attaches itself, if at all, only when adult, and usually to a very small peb- ble or bit of shell. It is hoped that the present account of the structure of this peculiar species of brachiopod will not only throw new light on the structure of Brachiopods in general, but also aid in more closely defining the new genus, the creation of which we owe to Prof. W. H. Dall. 1 It is now known to occur from tho South Florida Keys to Chesapeake Bay.
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