ON THE FOSSIL PHYLLOrODA OF THE PAL-EOZOIC ROCKS. 89 



typical, and know them as AptijcJwpsis prima, about 25 mm. long by 

 20 mm. in width ; and with the nuchal suture at an angle of 50°. Two 

 specimens in the British Museum (Natural History) in limestone from 

 Butowitz, and labelled ' Aptychus ? primus,' belong to this form ; also figs. 

 9-11 and 19 in pi. 33 of the ' Sil. Syst. Boheme,' &c. ; and two small 

 round individuals labelled ' Aptychus ? secundus ' (15 mm. in each 

 diameter ; nuchal suture with slope of 40°), in shaley mudstone from 

 Borek, belong to the varietal form, Aptychopsis prima, Barrande, var. 

 secunda. 



M. Barrande included with doubt another form in this genus — namely, 

 his Apiychopsis ? ivjiata, ' Syst. Sil. Bohem.' vol. i. Suppl, p. 459, pi. 33. 

 figs. 22, 23. But this seems to be an Entomis, and may stand as Entomis? 

 ■inilata (Barrande), from the hills between Lodenitz and Bubowitz, 

 Etage E e 2. 



There are no Goniatites in ' Etage E,' representing the lower part of 

 the ' Fauna III.,' which is equivalent to the Upper Silurian. There are, 

 however, some Goniatites (five species), rather higher up, in ' Etage F,' 

 which is in the middle part of ' Fauna III.' 



M. Barrande's careful and elaborate account of what was known of 

 Apiychopsis up to 1872 is almost sufficient in every respect. See the 

 ' Syst. Sil. Boheme,' vol. i. Suppl. 1872, p. 455. 



In the Sixth Report on Fossil Crustacea to the British Association 

 for the Advancement of Science, in 1872, Dr. Henry Woodward defined 

 some Phyllopodous species and grouped them under the same name (inde- 

 pendently arrived at) as M. Barrande proposed in the same year (see 

 above). See also Dr. H. Woodward's note on Peltocaris, Discinocaris, and 

 Apiychopsis in Nicholson and Etheridge's ' Fossils of the Girvan District,' 

 1880, pp. 210, 211. 



M. Barrande (op. cit. p. 455) states that Aptychopsis had been found 

 by Professor Angelin in Dalecarlia and Gothland in Upper Silurian strata 

 at about the same horizon as that in which they occur in Bohemia. We 

 cannot, however, learn of the existence of any Scandinavian specimens. 



2. Aptychopsis Wilsoni, H. Woodward, 1872. ' Sixth Report on Fossil 

 Crustacea — Report British Association for 1872, 1873,' p. 323 ; 

 ' Geo!. Mag.' vol. ix. 1872, p. 565. 



This species has a discoidal shield, and was briefly described, in 1872, 

 as having a straight (not circular) nuchal suture (making a triangular 

 cephalic plate) and a well-marked median or dorsal suture, and as mea- 

 suring Hmck in length, by If inch across. There are three specimens 

 of Aptychopsis Wilsoni in the British Museum, and they would probably 

 be almost round in outline if quite perfect. They are from the Riccarton 

 beds (Upper Silurian), at Shankend, Slitrig Water, near Hawick; Gad's 

 Linn, near Hawick ; and Elliottsfield, near Hawick, Dumfriesshire. 



We may add that the cephalic notch is not so deep as in some allied 

 forms ; its apex was about one-third of the length of the median suture 

 from the front edge of the shield. The usual concentric lines are apparent 

 on some specimens. 



One large specimen would measure 40 mm. in each diameter if com- 

 plete ; its nuchal suture slopes 40°. Another specimen (imperfect) 

 measures 30 mm. across, and has a nuchal slope of 60°; difference of 

 pressure has caused this discrepancy. 



