322 Prof. T. R. Jones on the 



millim.) and coarser ridges, however, are strong distinctions. 

 It has been much modified, the ridges having been squeezed 

 up into sharp edges ; and at the same time the upper margin 

 seems to have been flattened and broken and the sulcus nearly 

 obliterated. At one time I thought that it might match 

 Richter's E. Sandbergeri^ taking into account his bad 

 drawings ; but I cannot now reconcile the two forms, how- 

 ever much they may have been modified by pressure, particu- 

 larly as the ridges are spiral in Richter's fig. 17, pi. xx., 

 Zeitschr. deutsch. geol. (tbs. 1869, and they are simply 

 longitudinal and somewhat convergent at the ends in PI. XI. 

 fig. 3. As it is larger and more roundly oval (proportionally 

 higher) than E. serratostriata, with fifteen instead of about 

 thirty ridges, and therefore belonging to the thich-wrinJded 

 group, I separate this form as Entomis Richteri^ after my 

 deceased friend Dr. Reinhard Richter, who interested himself 

 for many years in the discovery and elucidation of many forms 

 of the Devonian Entomides in the neighbourhood of Saalfeld. 

 This specimen, from Whiteway Farm, is unique. 



3. Entomis gyrata (Richter). (PI. XI. fig. 4.) 



Cytherina, Eichter, Beitrag Palaont. Thiir. Waldes, 1848, p. 46, pi. vi. 



fig. 212. 

 Ct/pridina gyrata, Richter, Denksclir. Akad. Wissensch. Wien, vol. xi. 



1856, p. 122, pi. ii. figs. 33, 34; and Zeitschr. deutsch. geol. Gesell. 



vol. xxi. 1869, p. 769, pi. xx. figs. 13. 14 (bad figui-es). 

 Richteria {Entomis) gyrata, Bigsby, Thesaur. Bev.-Carbouif. 1878, 



p. 27. 

 Entomis gyrata, Jones, Ann. & Mag. Nat. Ilist. ser. 5, vol. iv. 1879, 



pp. 185-187, pi. xi. figs. 4, 8, 10-12, and 18 (From Dr. Richter's 



typical specimens.) 

 Entomis gyrata, Jones, Ann. & Mag. Nat. Hist. ser. 5, vol. xii. 1883, 



p. 245, pi. vi. figs. Za,Zb. (Uralian.J 



We know from G. West's careful figures (above referred 

 to) of Dr. Richter's own specimens what E. gyrata really is, 

 with its curious subconcentric wrinkling, which reminds us 

 (as Richter has noticed) of the delicate markings of our 

 finger-tops. The specimen before me, from Castle-dyke 

 Quarry, Devon, has its wrinkles, ridges, or costulge wide 

 apart and squeezed into sharp edges, and therein it differs 

 from the type ; but the pattern appears to be essentially the 

 same. When perfect the valve was about 1 millim. long by 

 0*7 millim. high, which is rather smaller than the German and 

 Uralian specimens. Rather than propose a new specific 

 standing for this unique specimen I place it with E. gyrata^ 

 on account of the plan of the ornament, though badly pre- 

 served. It may possibly be a variety of that species. 



