PERFORATING BODIES FROM LOWER PAL.^OZOIC ROCKS — ETHERIDGE.125 



they form a network, which spreads itself out in each layer, nearly 

 parallel to its surface ; so that a large part of it comes into focus 

 at the same time, in a section which passes in the plane of the 

 lamina." And again, "I have frequently seen in them indications 

 of a cellular origin, as if they had been formed by the coalescence 

 of a number of cells arranged in a linear direction." These tubes 

 were observed in various Bivalves, particularly Lima scabrosa, 

 Anornia ephijjpnwi, and in species of Chama* Dr. Carpenter's 

 illustrations! convey an excellent idea of some of the tubes in our 

 specimens. Carpenter evidently regarded the tubes as a portion 

 of the Molluscan economy, but later, Kiillicker pointed out that 

 all the more or less horizontally spreading tubes described by 

 Carpenter were those of parasites.; It is, however, only just to 

 state that Dr. Carpenter was afterward conscious of this, and 

 corrected § his earlier conclusions. 



In 1851 Mr. C. B. Rose investigated jj tubes perforating the 

 scales of recent and fossil fish, and looked upon them as "infusorial 

 parasites." 



Quekett's investigations of shell structure were equally success- 

 ful, for on referring to the subnacreous layer of Anomia, Lima, 

 and Area, he remarked*! : — -"The tubes sometimes run in a vertical 

 direction, but more frequently horizontally, between or upon the 

 laminte of which the shell is composed ; they are almost always of 

 uniform character, and very frequently branched, so that some of 

 them present very much the appearance of conferva. . . . Some 

 of these tubes presented a beaded appearance, indicating that they 

 are made up of cells like the tubular fibres of many fungi." 

 Quekett's tubes** are generally similar to those tubes permeating 

 the Favosites, but perhaps a little too regular and too much 

 branched, but not so others seen in a Rice-shell, ff 



In 1858, Mr. 0. Wedl described! J tubes traversing the tests of 

 Brachiopoda, Univalves and Bivalves, but his illustrations do not 

 bear particularly on those now under description. He likened 

 them to the living Saprolegnia ferax, which he regarded as a 

 Confervan. About the same time Kollicker showed§§ that similar 



* Ibid., 1847 (1848), p. 100. 



t Ibid., 1844 (1845), pi. ix., fig. 20, pi. xviii, fig. 4. 



j Proc. Roy. Soc. xx., 1859, p. 97; Quart. Journ. Micro. Soc, viii., 1860, 

 pp. 172 and 181. 



§ The Microscope, 6th Edit., 1881, p. 382. 



II Fide Duncan, (I have not seen the paper). 



IT Lectures on Histology, ii., 1854, p. 276. 



** Loc. cit., fig. 162. 



ft Loc. cit., fig. 163 B. 



++ Sitz. K. K Akad. Wissensch., xxxiii., 28, 1858, p. 451. 



§§ Proc. Roy. Soc, x., 1859, pp. 96-98; Quart. Journ. Micro. Soc, viii., 

 1860, pp. 172 - 181. 



