Palceozoic Bivalved Entomostraca. 401 



ventral lobe. Fig. 21 of the same plate is possibly a larger 

 (older) individual of the same variety. 



Boll's B. spinigera (Archiv Ver. Fr. Naturges. Mecklen- 

 burg, 1862, p. 133, pi. i. ^g. 7) is much like the variety under 

 notice, but the middle lobe is quite distinct from the other 

 two, and the margin has a different ornamentation. B. nodu- 

 losa, Boll {L c. fig. 6), also belongs to the same category, but 

 the lobes have different proportions and position. B. pro'- 

 tuherans^ Boll (/. c. fig. 6), is a weaker variety, tuberculate 

 only on the hinder lobe, and deformed in front by the usual 

 hypertrophied lobe. 



4. Beyrichia KlmdeMt^ M'Coy, var. antiquata, Jones. 



Beyrichia Kladeni, !M'Coy, var. (mtiqunta, Jones, Ann. & Mag. Nat. 

 Hist. ser. 2, vol. xvi. 18o5, p. 167, pi. vi. fig. 8 ; Palasoz. Biv. Entom., 

 Geol. Assoc. 1869, p. 12, pi. xiv. fig. 7 (in both instances the sinistral 

 valve is figured and is erroneously termed the dextral) ; Geol. Mag. 

 1881, p. 345, pi. X. fig. 11 ; Silur. Ostrac. Gothland, 1887, p. 2. 



Some years ago I received this specimen from Prof. Lind- 

 strom. It occurred in the shale of QEstergarn, Grothland. 



Fig. 14 in Angelin's unpublished " tab. A " is evidently 

 B. Klosdeni, var. antiquata, 



5. Beyrichia Kloedem, M'Coy, var. tiibeixulata, Salter. 



(Geol. Mag. 1881, p. 345, pi. x. fig. 13 ; Ann. & Mag. Nat. Hist. ser. 5, 

 vol. xvii. 1886, p. 354, pi. xii. figs. 8, 9 ; Silur. Ostrac. Gothland, 1887, 

 p. 3.) 



This variety is shown by one of the drawings sent from 

 Stockholm. A few specimens were found in the uppermost 

 limestone of Linde klint. From the shale at Frojel I have 

 one specimen, sent some years ago. 



B. Kladeni, var. tuberculata, was first described and 

 figured by Mr. J. W. Salter in 1848 (Mem. Geol. Survey, 

 vol. ii. part 1, p. 352, pi. viii. figs. 14, 15) as "jB. tuhercidata, 

 Kloden/' Figs. 14 and 14 a represent the outside of the 

 valve, from the Wenlock Limestone at Lindells, Woolhope ; 

 figs. 15 and 15 a show an internal cast from the Wenlock 

 Shale, at Tynewydd, south of Llandovery. 



In this variety the width of the ventral margin and the 

 amount of tuberculation vary very much with individuals. 



In Angelin's unpublished " tab. A/^ fig. 18 evidently 

 represents this variety. 



6. Beyrichia Bolliana-umhonata, Heuter. 

 (PL XXL figs. lO&ll.) 



Some specimens under notice are probably identical with 



