274 



HARD Wl CKE 'S S CIE NCE - G SSI P. 



R. fragilis, red when young, but white and polished 

 afterwards, viscid. Another common species is Rus- 

 stila nigricans, dark greyish green or dingy olive, 

 becoming charred as well as the stem, when old ; 

 umbilicate, as are the Russulas generally, and with 

 the margins of the elevated borders inflected ; the 

 gills are white with a black border. 



Cantharellits cibarius is sometimes plentiful in 

 Epping Forest. It may be known by its golden- 

 yellow colour, infundibuliform pileus, and gills re- 

 duced to mere folds or swollen veins. We could 

 obtain no specimen to illustrate this curious structure 

 of hymenium. The genus has a floccose trama ; 

 gills in other species thick, swollen, and obtuse. 



Marasmins is another genus in which the trama is 

 floccose; the hymenophorum confluent with the 

 stem, although of different structure; not confined 

 to the lamellae, but spread over all the interstices. 

 M. Oreades is said to be good eating, grows on dry 

 pastures, generally in rings (the circle is rarely com- 

 plete) of from six to eight feet broad. The whole 

 plant is of a dirty cream-colour, pileus more or less 

 slightly stained with brown, and seldom more than an 

 inch or two in diameter. We found them on a com- 

 mon near Woodford. 



Intermediate between the gillbearing Hymenomy- 

 cetes, and those with a porous hymenium, are the two 

 curious genera, Zeuzilesand D&dalea, both of common 

 occurrence in forests, and of which the former is 

 retained in the first-mentioned family, and Dadalea 

 in the latter ; but the fact is, when fully developed, it 

 is very difficult, out of a number of specimens, to 

 decide which is which. Nature is very unaccommo- 

 dating, and refuses to be tied hard and fast by laws 

 and rules, as laid down in the books which treat of her 

 phenomena. The lamellae of Dcedalea are indeed 

 sometimes so much broken up, in old plants, as to 

 resemble the toothed processes characteristic of the 

 hymenium of a Hydmim. 



FOSSIL FOLYZOA. 



The Genus Fenestella: its History, Develop- 

 ment, and Range in Space and Time. 



By George Robert Vine. 



History of the Genus. 



IN these papers I do not wish to discuss questions 

 that are purely geological. I wish to deal only with 

 one type of a class, out of many of the classes which 

 fall naturally into the divisional roll of the palaeon- 

 tologist. But while keeping this before me as a 

 guide, I cannot ignore the fact that in speaking of 

 formations it will be necessary to either enlarge or 

 restrict my meaning when I use certain terms. In 

 speaking of the Silurian System, this was not so 

 much needed, but in speaking of the Fenestella of the 



Devonian system it will be necessaiy to limit my 

 meaning, as my remarks on the species will apply 

 more particularly to the typical Devonian rocks of 

 Devon and Cornwall. 



In 1 84 1, Mr. John Phillips published his elaborate 

 work on the Geology of Cornwall, Devon, and West 

 Somersetshire. In this work there are numerous 

 plates of Fossils, with letterpress descriptions of the 

 same. Figures and descriptions are given of these 

 species of Fenestella, for in this work Phillips discards 

 the word Retepora, and uses Miller's more expressive 

 term. The specific character of F. laxa is similar to- 

 that given in his Geology of Yorkshire. ' ' The net- 

 work is extremely large and irregular, the obverse 

 bearing two rows of tubular pores, reverse granulously 

 striated," and the localities are S. Petherwin and 

 Croyde. Of the F. antiqua Goldfuss, Phillips gives 

 several very good figures, and his description is little 

 more precise. He says of one of his figures (35«), 

 F. antiqua var. that the specimen was sub-conical, and 

 that the celluliferous face was external. This is clearly 

 a mistake, for even from the figure it seems to give an 

 idea that the polyzoon was parasitic on some object. 

 The corallum was irregular, with thick, slightly 

 flexuous interstices, very obtusely carinated ; the 

 dissepiments were thick and short, and placed at 

 regular intervals ; the fenestrules were oblong, and 

 the pores were small, with slight prominent margins 

 about their own diameter apart, and usually 

 about three to the fenestrule. The species and 

 varieties are common in the Devonian Limestone of 

 Plymouth. This description applies to Goldfuss' 

 figure of Retepora antiqua, and not to Lonsdale's 

 F. antiqua of the Silurian System. F. anthritica is 

 another of the Devonian species, but it is not very 

 well described. The figures are very good, but I 

 cannot make much out of them. The Hemitrypa 

 oculata of South Devon seems to me to be clearly 

 a Fenestella. It is a thin laminar expansion in 

 a cup-formed mass. The external surface is wholly 

 covered with numerous round pores or cells radiating 

 from a centre, and associated in double rows, which 

 near the centre undergo frequent divisions, so as to 

 form two such rows. The figures seem to bear, in 

 some respect, the character of Hemitrypa Hibernica, 

 and also to the Fenestella {?) Sykesii of De Koninck. 

 One of Phillips's drawings, fig. 38 E., is decidedly 

 characteristic of the Fenestella type, and one would 

 have no hesitation in placing it with that group. I 

 have been rather more particular with Phillips's 

 Devonian Fenestella than I should have been had the 

 work been less scarce. As it is, I have done my best 

 to furnish the student with his specific characters in 

 this history of the Genus. 



Several American Devonian species of Fenestella 

 have been figured and described by H. A. Nicholson, 

 Professor of Biology, in his work on ' ' Ontario," and in 

 the Geological Magazine for 1874-5. Some of these new 

 forms are very characteristic, and although they bear 



