HARD WICKE 'S SCIENCE- G OSSIP. 



249 



Lonsdale — not having his works at hand to refer to — 

 but the following is taken from M 'Coy's " Palaeozoic 

 Fossils " : — " Polypidom calcareous, cellular, forming 

 a conical or fan-shape expansion of radiating branches, 

 interstices connected by transverse dissepiments ; 

 exterior surface of branches rounded, covered by 

 tlense minutely porous layers ; inner surface with a 

 keel along the middle, separating two rows of mouths 

 of short tubular cells, which extend a variable length 

 obliquely downwards and inwards into the interior of 

 the branch : dissepiments usually without cells, 

 occasionally a row of small cells on the mesial keel. 

 Non-celluliferous side formed internally of a layer of 

 vertical capillary tubes." This genus was placed by 

 M'Coy among his Family, Group Myriaporid.'E, a 



Fig. 205. Fenestella with lateral ralicocoryue. a. Bases of cells partially 

 exposed, b. Immature development of Fenestrule with PaUeocoryue 

 (b) on reverse. The wider openings are the fenestrules, very irregular 

 in shape and size. The specimen is upside down, to show the connec- 

 tion on the branches. (Natural size, slightly over \ of an inch. 



group which embraced the genus Retcpora of 

 Lamarck ; the Elasmopora of King ; the Glanconome 

 of Goldfuss restricted by Lonsdale ; the Penniretopora 

 of Prodomas ; the Acanthocladia of King ; together 

 with the sub-genera Fcncstdlina and Reteporifia of 

 D'Orbigny. 



The first recorded appearance of this genus is in 

 the Bala beds of the Lower Silurian series. In Morris's 

 Catalogue, and also in Jukes's " Student's Manual," 

 1857, it is recorded as appearing in the Upper 

 Silurian, in company with many other forms of 

 Polyzoa. In the later edition of the Manual this 



may have been corrected, but I have not seen it. 

 But in Morris's earlier Catalogue, which he began in 

 the 1st volume of the Geologist, Fencstella snbantiqna, 

 D'Orb., and F. Milleri, Lonsdale, are given with the 

 Lingula, Llandello, and Caradoc or Bala Bed fossils. 

 From either the figures or even the specimens, it is 

 very difficult to make out the true character of 

 F. Milleri. The habit of the species as impressed 

 upon the Bala shale is peculiar and characteristic. 

 It is partially flabelliform, but not universally so, as 

 some of the branches cross and recross the under ones ; 

 thus obliterating the true character. The interstices 

 are thin, and according to the description, the dissepi- 

 ments are narrow and slender, and two lines apart. 

 The fenestrules are five or six times longer than wide, 

 with about twelve pores to the fenestrules. 

 If this be a true description of the species, 

 F. Milleri is a marvellous specimen of the 

 earlier Fenestella group. Fenestella Lons- 

 dalei, D'Orb., is figured in Sihtria, and is 

 given by Morris in the earliest, as in the 

 latter catalogue. It is found in the Dudley 

 limestone as well as in the lower beds, 

 and if the synonyms be true, the species 

 had a very wide range, as it is figured as 

 an American species as F. prisca, and 

 Morris, in his catalogue, gives F. prisca 

 as a synonym of the species. The figure 

 before me is cup-shape, attached by a 

 broad base to some foreign object. The 

 outline of the margin of the cup-like form 

 is entire, and the poriferous face will be 

 on the inside, like modern species of 

 Retepora and Hornera. It seems to be a 

 good species, and habit alone would be a 

 sufficient character. F.snb-antiqna, D'Orb., 

 is another Silurian Fenestella ; but among 

 synonyms of this are given F. antiqna, 

 Lonsdale, Retepora antiqna, Goldfuss, and 

 R. membranacca, Phillips : it may be a frag- 

 ment of some larger specimen of F. prisca. 

 D'Orbigny's species, as recorded and de- 

 scribed in his Palaeozoic Fossils, has a 

 corallum very slender, with straight inter- 

 stices, seven or eight of these measuring 

 only two lines ; the dissepiments are thick, 

 and the fenestrules are rectangular or 

 oblong, about three lines longer than wide. The 

 pores are small, thick, with prominent edges, their 

 own diameter apart, and six or seven to the length of 

 the fenestrules. F. reticulata, Lonsdale, is a species 

 that has been often confounded with Hisinger's 

 Retepora, so much so, that M'Coy draws attention to 

 the fact, acknowledging that it is scarcely possible to 

 determine the specific character, as no information is 

 given relative to the pores. Yet, as his species of 

 Retepora Ilisingeri ? agrees in some particulars with 

 the original, he would even add confusion to the con- 

 fusion, and name it R. retifonnis, even though Mr. 



