Reviews — Dr. F. A. Bather — Cystideans from Girvan. 419 



Gallery of the British Museum, and, at a much later date, the 

 Brachiopoda and the Tunicata (1851-6) were still retained in 

 textbooks in the same phylum, as a part of the Malacostraca. 



As palaeozoologists we are much indebted to Dr. F, A. Bather for 

 having undertaken the study of the Echinoderma, of which he says it 

 is "one of the best characterized and most distinct Phyla of the 

 Animal Kingdom ". Notwithstanding this encouraging introduction, 

 we venture to think that this division contains many very difficult 

 organisms to investigate, to which the author has devoted long years 

 of careful and diligent study and made extensive acquaintance with 

 both the literatui'e of the subject and the specimens to be described. 

 Particularly we must thank him for that admirable volume in 1900 

 on the Echinoderma.' In it Dr. Bather writes: " JN^early all the 

 living animals included in this phylum, such as the sea-urchin 

 (Kchinoid), starfish (Asteroid), brittle-star (Ophiuroid), sea-cucumber 

 (Holothurian), and sea-lily (stalked Crinoid), or feather-star (free 

 Crinoid), can readily be distinguished through their possession of 

 a radial symmetry, in which the number five is dominant ; of a sub- 

 epidermic skeleton composed of calcium carbonate with a characteristic 

 micro-structure resembling trellis-work, and of a system of sacs, 

 canals, and tubes that carry water through the body, especially 

 by means of five radial canals from which small branches cslledi podia 

 are given off to the exterior. The extinct forms known as Blastoidea 

 and Edrioasteroidea appear to have had a similar organisation, and 

 the same statement may be made of most of the Cystidea" — the class, 

 which forms the subject of the present monograph. 



In this his latest work the author presents us with a description 

 of the Cystidea (one of the three extinct and most aberrant classes, 

 of the Echinoderms), collected from the Caradoc Beds (Ordovician) of 

 Girvan, Ayrshire, by Mrs. Robert Gray, who has done so much ta 

 add to our knowledge of the fossils of this now historic locality. 

 In this undertaking she has been fortunate in having had the 

 co-operation of various palaeontologists, including the late Professor 

 H. A. Nicholson, Mr. Ilobert Etheridge, jun., Mr. F. R. Cowper 

 Reed, Dr. F. A. Bather, and others. 



"Though written" (says Dr. Bather) "in order to describe Girvan 

 materia], the memoir has grown to be little less than a monograph 

 of the genera dealt with, and even includes the description of a new 

 species from Bohemia. For this no apology is required. When 

 a group of organisms has recently received adequate revision, new 

 forms may on occasion be merely described and referred to their 

 systematic position. In the present instance, prolonged study of 

 allied species and genera proved a necessary preliminary to the 

 understanding of the Girvan fossils, and if the descriptions of the 

 latter are to be intelligible the reader must first be placed at the same 

 point of view as the writer." 



To show the geological distribution in Girvan of all the Cystid 

 remains, both described and undescribed, the author adapts a portion 



^ Contributed to Sir E. Ray Lankester's Treatise of Zoology (assisted by 

 Dr. J. W. Gregory and E. S. Goodrich), 8vo, 1900, pt. iii, pp. viii-F344, 

 and 309 text-figures. 



