ON THE FOSSIL PHYLLOPODA OF THE PAL^O;:OIC ROCKS. 521 



short process ; and the postero-ventral with a strong, sharp, trigonal 

 spine. 



The straight hinge-line is defined by two small dorsal notches. The 

 ventral border has a striated, serrated, or fringed margin, either on its 

 posterior moiety or throughout its extent. 



The surface of each valve bears one longitudinal (meso-lateral) ridge, 

 and sometimes others parallel ; also short ridges (cephalic) over the gastric 

 apparatus, and slighter ridges (nuchal) near the top of the dorsal ridge, all 

 more or less rugose. 



Scattered granulations and tubercles are often present on some parts 

 of the valves, also lines and reticulations. 



Granulation is feeble and sparse on D. glabra and D. ovalis ; strong 

 and abundant on D. gramdata. Small prickles, rising from the meshes of 

 a reticulation, are scattered over D. tricornift, D. Colei, and J), orbicu- 

 laris ( ?). A system of oblique transverse lines characterises J), testudinea. 

 A feeble reticulation is traceable on D. funiculata and D. Scouleri (?). 

 Longitudinal striae mark the surface in D. Belli and J), striata ; and D. 

 temcistriata and D. Youngii have longitudinal costul*. 



In consideration of certain differences in the carapaces, we separate 

 Nos. 10 and 11 of the Table, at page 2, from Dithyrocaris, as Chcenocaris 

 tenuistriata and Ch. Youngii, the carapace being bivalved and gaping. 

 There is also an obscure Devonian form, from Saalfeld, to which we refer 

 as Chcenocaris Richteriana. We regard No. 1 2 as having a closed bivalved 

 test, and therefore designate it as Calyptocaris striata. 



We have had the opportunity of studying an old Apus-like fossil 

 labelled ' Burdiehouse.' It shows a small circular carapace (measuring 15 

 by 13 mm.), with strong postero-ventral angles, and distinct meso-lateral 

 ridges leading to them ; also a slightly curved depression in the middle of 

 the front border, and a granulated margin throughout. 



Mr. E. J. Garwood, F.G.S., who is a member of the British Association 

 Committee for defining the zones in the Carboniferous rocks, has just now 

 forwarded for our examination a very interesting collection of the remains 

 of Dithyrocaris from excavations in the shales of the Millstone-grit series 

 at Eccup, Yorkshire. 



§ II. In the ' Proceed. United States National Museum,' vol. xix. 1897, 

 Mr. C. Schuchert has a paper ' On the Fossil Phyllopod Genei'a Dipeltis 

 [Packard emend.^^ and Protocaris.' The latter was noticed in our Report 

 to the Association for 1889, p. 64, and in our Ninth Report (for 1891), 

 p. 300. The original genus Dipeltis was established by A. S. Packard, in 

 the 'Memoirs of the National Academy of Sciences,' vol. iii. 1885, Mem. 

 xvi. p. 1 45, pi. V. figs. 2, 2«, as one of the Carboniferous Xiphosura of North 

 America. In the December number of 'Natural Science,' 1897 (vol. xi. 

 p. 401, figs. 2-5), in his paper on 'Fossil Apodidre,' Mr. H. M. Bernard 

 follows Mr. Schuchert in regarding the Dipeltis, as defined by the latter, 

 as a Phyllopodous Apus-larva. Mr. C. J. Gahan, however, in ' Natural 

 Science,' January 1898, pp. 42-44, points out that it is really a larval form 

 of the Blattarian Insect ^<o6^a«Mia, described and figured by H. Woodward 

 in the 'Geological Magazine,' 1887, p. 433, pi. xii. 



§ III. With reference to the Bohemian ^s</teHfe mentioned at page 4 of 

 our Report for 1893 (Tenth, 1894), Dr. Anton Fritsch has informed us that 

 they were named by him in the ' Sitzungsb. k. bohm. Gesellsch. Wissen/ 

 1894 : No. 1 being Estheria triangularis, Fr. ; No. 2, E. cyenea, Fr. ; 

 No. 3 [and No. 4 ?], E. 2>alcconiscorum, Fr. ; and No. 5, E. calcarea. 



