152 Mr. F, Chapman on some 



(Kloeden). Six of such varieties are figured on pi. xxi. 

 Ann. & Mag. Nat. Hist. ser. 6, vol. i. (1888) p. 402, 

 figs. 12-17, from the Silurian of Slite, Gotland. In the 

 present instance the lobes are more distinctly marked with 

 three obliquely transverse furrows; the ventral edge more 

 neatly tubercled, and the two bold curved venfral fringes far 

 more synimetricully arranged. Length 2'5 millim. ; height 

 1"4 millim. 



Silurian ; Mulde, Gotland. Frequent. 



Beyrichia BolUana umhonata, Renter. 



Beyrichia Bolliatia umbonata, Renter, 18So, Zeitsclir. deutsch. geol. 

 Uesellsch. vol. xxxvii. p. 046, pi. xxvi. lig. 21 ; Jones, 1883, Ann. & 

 Mag. Nat. Hist. ser. 6, vol. i. p. 401, pi. xxi. figs. 10, 11. 



This species has been recorded from Frojel. Two specimens 

 were found at Mulde and are variable in size; their lengths 

 measure 1'3 millim. and 2'3 millim. respectively. 



Silurian J Mulde, Gotland. 



Beyrichia chivata, Kolmodin. 



Bet/riihia clavata, Kolmodin, 18G9, Bidrag till Kiinnedomen om Sverges 

 Siluriska Ostracoden, p. 18, fig. 10 ; Jones, 1887, Silur. 0.<trac. Goth- 

 land, p. 2 ; Jones, 1888, Ann. & Mag. Nat. Hist, ser, G, vol. i. p. 399, 

 pi. xxi. figs. 6-9. 



The washings from Mulde have yielded a very large 

 number of this species, a fair proportion of them having tlie 

 hypertrophied lobe common to this type of Beyrichia. 

 Prof. Jones records B. clavata from Eksta and Frojel in 

 Gotland. 



Silurian; Mulde, Gotland. Very abundant. 



Family Cytheridse. 



Cythere, Miiller [1785], 



? Cythere Vinei, Jones. 



? Cythere Vinei, Jones, 1887, Ann, & Mag, Nat, Hist. eer. 5, vol. xix. 

 p. 191, pi. vii. figs. 1 a, 6, & 5 a, 6. 



A specimen similar in every respect to those found in the 

 Wenlock Shales of Shropshire was met with in the Gotland 

 series. The generic relationship of this and the following ia 

 very doubtful. 



Silurian ; Mulde, Gotland. 



