88 Reviews — Palceozoic W or vis and Hydro ids. 



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Paleozoic Wokms and Hydroids in Victoria. 



CHAPMAN (1919, Proc. Roy. Soc. Victoria, vol. xxxi, pp. 315- 

 24, j)ls. xiii, xiv) claims to have found the gill-j^lumes of 

 the Silurian worm TracJiydenna, well j)reserved in the Melbournian 

 Mudstones near Keilor, Victoria. This evidence confirms the usual 

 reference of the fossil to the Chsetopoda, and suggests that it belongs 

 to the Sabelliformia. Mr. Chapman regards Eotrophonia setigera 

 'El. 0. Ulrich, 1879, as similar gill-plumes. This came from the 

 Lower Cincinnatian beds of Covington, Kentucky, not from 

 Cincinnati itself. Mr. Chapman also describes a new Cornulites 

 (C. youngi) from Lower Ordovician slates with Didymograptus 

 caduceus, on the Moorabool River north-west of Geelong, and claims 

 it as the oldest recorded. On the evidence of a flattened basal 

 attachment, Mr. Chapman believes that this genus as well as 

 Pterocomis Hinde {=N ereitojosis Green) is a tubicolar Chaetopod. 



In another paper (tom. cit., pp. 388-93, pis. xix, xx) Mr. Chapman 

 refers some finely preserved specimens from the Lower Palseozoic 

 Lancefield slates to the Hydroid Order Calyptoblastea, under 

 the names ArchcBolafoea n.g. and ArchcBocryptolaria n.g. He also 

 refers to the same Order the Chaunagrap)tus and Mastigograjjtus 

 of Ruedemann, and describes a new species of the latter as M. mone- 

 gettcB. (See Plate XV in Geological Magazine, December, 1919.) 

 The discovery is an interesting one, for, with doubtful 

 exceptions in the Pleistocene, the only fossils hitherto assigned 

 to this Order are the Dendrograp tides. Until representatives have 

 been found in the intermediate strata, sceptics will doubt the 

 lineal descent of modern Sertularians and their allies from these 

 ancient forms, however great the external resemblance may be. 



A Study op the Brachiopod genus Platystrophia. By 

 Eula Davis McEwan. Proc. U.S. National Mus., vol. Ivi, 

 1919, pp. 383-448, pis. 48-52. 



rriHIS is a study of the North American species of the well-known 

 -*- Ordovician and Silurian genus Platystrophia, leading to a 

 systematic arrangement based on their supposed evolutionary 

 history. We say " well-known ", but, as Miss (or Mrs.) McEwan 

 points out, the determination of the genotype — Terehratulites 

 biforatus Schlotheim — is still uncertain. She therefore selects 

 as a new genotype Platystrophia laticosta Meek, 1873. This action 

 is surely ill-advised, even if admissible. Two alternative courses 

 are open to a reviser. First to attempt the fixation of the genotype. 

 Schlotheim's description, unaccomj)anied as it is by a figure, may be 

 unintelligible to a modern palaeontologist, but this may only be 

 because of his larger acquaintance with allied forms and his more 

 minute discrimination. Von Buch, we are told, saw the holotype 

 in the Berlin Museum, and had no difficulty in pointing out the 



