472 Notices of Memoirs — G. R. Vine on Fossil Pol//zoa. 



II. Ctclostomata. — The simplicity of structure in this sub-order 

 precludes elaborate description. There are, however, a few points of 

 special structure to which it may be as well to direct attention. Tlie 

 cells are invariably tubular, or nearly so ; the mouths are circular, 

 and, generally speaking, of the same diameter as the cell. The cell- 

 mouths in many of the Cyclostomata are covered by calcareous 

 opercula, in both recent and fossil species, and these are considered 

 to be — by Mr. F. D. Longe^ — of an analogous character with the 

 corneous opercula of the Cheilostomata. Be this as it may — all the 

 Cyclostomatous opercula are calcareous — and their use has not yet 

 been definitely made out. 



In his classification of the British Marine Polyzoa, Mr. Hincks 

 bases his genera and species, to a large extent, upon the shape and 

 character of the cell and cell-mouth, — the habit of species is only 

 of secondary importance. To working naturalists amongst living 

 species his carefully worked-out divisions are of supreme importance, 

 and the Palgeontologist may do well to carry over the leading idea 

 of Smitt and Hincks when working out fossil species, especially so 

 when dealing with Palaeozoic types. It may be well, too, to caution 

 the student in his use of the generic names of the earlier authors. 

 These have to be revised according to modern usage. In every case 

 where I could retain the original designation of the author of genera 

 and species I have done so, but it seems to me to be a folly to 

 perpetuate a nomenclature which does not indicate generic affinity. 

 In his otherwise carefully written " Introduction," Mr. Hincks says, 

 " There is evidence, however (as I learn on the excellent authority of 

 Mr. E. Etheridge, jun.), of the existence of a few Cheilostomatous 

 genera at least within this epoch (PalEeozoic), and probably the 

 group is represented in the Silurian division of it"^ — a conclusion 

 which, after the most careful research, I am unable to agree with. 



In this, as in my former Eeport, I shall revise the whole of the 

 genera and species that have been introduced since the time of 

 Goldfuss into the nomenclature of Silurian and Devonian literature. 

 I would prefer to deal only with British species, but as many papers 

 describing new genera and species, from foreign sources, have been 

 published in this country, I cannot do otherwise than review, if not 

 revise, these as well. But whereas, in my former Eeport, I dealt 

 generally with material in my own cabinet, in this I shall refer 

 largely to the Polyzoa in the magnificent collection of the Museum 

 of Practical Geolcgy. For this purpose I have handled, and noted 

 down jjarticulars of every specimen in the collection, from the 

 Lower Silurian to the Devonian. This I have been enabled to do 

 through the kindness of Mr. Etheridge, F.E.S., Palaeontologist, and 

 Mr. E. T. Newton, Assistant Naturalist of H. M. Geological Survey, 

 Museum, Jermyn Street. 



Professor Duncan has expressed a wish that in this Eeport I 

 should draw up a suggestive Terminology, that would be in keeping 



1 Oolitic Polyzoa, F. D. Longe, F.G.S., Geol. Mag., January, 1881. See also 

 Hincks's Brit. Marine Polyzoa, Introduction, p. cv, and pp. 460- 1. 



2 Brit. Mar. Poly. p. cxviii. Adding in a note, " Of recent genera Slotnatojm-a and 

 Diastopora appear to occur in the Silurian Eocks." 



