PTYCHOCARIS JASCHEI. 193 



Characters. — Style (telson) broad, stout, and tapering ; shorter than the 

 stylets. The inner margin of the stylets is fringed with setas. 



2. Mesothyra ocbani, Hall and Clarice, 1888. 



Dithtrocaeis neptuni, Hall, 1876. Illustr. Devonian Foss., pi. xxii, figs. 1 — 5, 



pi. xxiii, figs. 1 — 3. 

 — — E., W., and J., 1888. Report Brit. Assoc, for 1887, 



p. 65. 

 Mesothyea oceani, Hall and Clarke, 1888. G-eol. Surv. New York, Palaeont., 



vol. vii, p. 187, pi. xxxii, figs. 1 — 6 ; pi. 

 xxxiii, figs. 1 — 7 ; pi. xxxiv, figs. 1 — 5. 



r Carapace-valve (including posterior spine) 140 mm. long, and 60 mm. 



wide. 

 I Caudal plate and telson [style including head] 67 mm. long. 

 Size <j Cercopods [stylets] 70 mm. long. 



Carapace-valve 150 mm. long, and 65 mm. wide. -\ 

 Style 72 mm. long; wide at head, 2-1 mm. > As figured. 



LStylets 84 mm. long ; wide at top, 13 mm. J 



Characters. — Stylets vary in length, but are longer than the style. Setas are 

 attached to the inner margin of the stylets. 



One Devonian specimen that has been referred to Dithyrocaris may be here 

 noticed. 



Ptychocaris? Jaschei (F. A. Roemer, 1855). Plate XXIX, figs. 15 a — c ; and 16 a, b. 



Dithteocaeis Jaschei, F. A. Roemer, 1855. Pala?ontographica, vol. v, p. 8, pi. ii, 



figs. Via— c; aud vol. xiii, 1866, p. 219, referring to 



Roemer' s Beitrag III, pi. xvii [ii], fig. 13 (misspelt 



Ditryoeharis). 



Dithyeocabis? Jaschei, Kayser, 1878. Abhandl. Geol. Specialkarte von Preussen 



und Tliiiringischen Staaten, vol. ii, Heft 4, p. 7, 



pi. i, figs. 13, 13 a. 



— Jaschei, J. M. Clarke, 18S4. N. Jahrb., 1884, vol. i, p. 185. 



— ? - K, W., and J., 1888. Report Brit. Assoc, for 1887, 



p. 66. 

 Pttciiocaeis ? Jaschei,^., W., and J., 1889. (After Novak.) Rep. Brit. Assoc. 



for 188S, p. 124. 



26 



