APTYCHOPSIS. 99 



M. Barrande's careful and elaborate account {op. elf.) of what was known of 

 Aptychopsis up to 1872 is almost sufficient in every respect. 



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 (independently arrived at) as 

 M, Barrande proposed in the same year (see above). See also Dr. H. Woodward's 

 note on Peltocaris, Disrinocaris, and Aptijcliopsis in Nicholson and Etheridge's 

 ' Fossils of the Girvan District,' 1880, pp. 210, 211. 



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

 Aptycliofsis ? inflata, ' Syst. Sil. Bohem.' vol. i; Suppl. p. 459, pi. xxxiii, figs. 22, 

 23. But this seems to be a Bolbozoe, and may stand as Bolbozoe? inflata 

 (Barrande), from the hills between Lodenitz and Bubowitz, Etage B, e 2. 



There are no Goniatites in 'Etage B,' 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 " Stage F," which is in the 

 middle part of " Fauna III." 



We have to remark that in Aptychopsis the form and proportions of all three 

 valves (lateral and rostral) and their relative position have been so much altered 

 by pressure and other accidents of fossilisation that it is often difficult to fix upon 

 safe data for judging of the exact relationship of the different forms. This is 

 especially the case with the size and angle of the nuchal notch, which, as Barrande 

 has suggested, may have differed with the age of an individual. Therefore the 

 shape of the carapace and of its two lateral moieties or valves, and the character 

 of their ornament, are to be chiefly considered. The following are the recognisable 

 forms of Aptyclwpsis which we have met with : 



Bohemian. 1. A. prima, Barrande, op. cit., pi. xxxiii, figs. 10, 12, 16, 19— 21.»v 



Obovate, subcircular. / Tipper 



— — var. longa, nov. Loe. cit., fig. 11. Obovate, long. f Silurian. 



— — var. secunda. Loc. cit., figs. 1—9, 13—15, 18. Circular. J 

 British. 2. A. Sarrandea7ia, s-p. nov. PI. xv,flg. 1. Obovate, long, tapering pos- "\ 



teriorly. f Tpper ? 

 2*. — var. brevior, nov. Obovate, tapering pos- C Silurian. 



teriorly. J 



— 3. A. cordiformis, sp. nov. PI. xv, fig. 2. Obovate, acute posteriorly. Middle ? Silurian. 



4. A. lata, sp. nov. PL xv, fig. 6. Obovate, broad, subcircular, acute posteriorly. 



Middle ? Silurian. 



Bohemian?") ^. , „ tt c.-i • 



and [ 5. A. glabra, H. Woodvsrard. PL xv, fig. 11. Circular, small. Upper hilurian. 



British. ) 

 British. 6. A. Wilsoni, H. W. PL xv, figs. 12 (?), 15, 16. Circular, large. Upper Silurian. 



Bohemian ? "^ 7 ^ Lapworthi, H. W. (Barrande, op. cit., pi. xxxiii, fig. 17 ?). PL xv, figs. 7. 3, 

 and > jQ g^ 9^ 22.' Oval. Middle Silurian. 

 British. ) ' ' 



The order of similarity or relationship is thus indicated here and elsewhere. 



