396 



DR F. A. BATHER. 



Dendrocystis rossica. 

 (Text-figs. 10-12.) 



1901. Dendrocystites rossicus 0. Jaekkl, Zeitschr. deutsch. geol. Gesell., vol. 52, p. 673. 



§ 150. Diagnosis. — A Dendrocystis with distal region of stem compressed, with 

 dimeres alternate to subalternate and keeled. 



§ 151. Locality. — Near Kuckers, Esthland. 



§ 152. Horizon. — " Brandschiefer," C2 of F. Schmidt, usually regarded as corre- 

 sponding in time to the Upper Llandeilian ; Bassler (1911, p. 38) correlates it with 

 the upper part of the Black River Group. 



§ 153. Material. — Brit. Mus. E7653, viz. two isolated dimeres (a and b) and one 

 columnal of united dimeres (c), being syntypes presented by Prof. Jaekel out of his 

 original material, which has never been described. 



Text-figs. 10-12.— Dendrocystis rossica. Drawn from Brit. Mus. E7653, enlarged 2 diameters. 



Fig. 10. — Restoration of a part of the distal region of the stem. 



Fig. 11. — Inner face of dimere «, showing the lumen, ^fote the slight locking tooth at the top 



of the proximal slope. 

 Fig. 12. — Distal joint-face of the same dimere. 



Text-fig. 13. — Dendrocystis (?) -paradoxica. Outline of the holotype, traced from Billings' 



original figure ; natural size. 



§ 154. Description. — No other part of the fossil was mentioned by Prof. Jaekel, but 

 he tells me (in litt. June 29, 1912) " es war sicher ein Kelch an dem Stiel, und meines 

 Wissens auch oben das ' arm '-artige Organ." Unfortunately he has not been able to 

 lay his hand on the specimens, so my remarks must be confined to the distal region 

 of the Stem. 



In E7653 c the dimeres form at one end an almost level joint-face ; but since they 

 are of unequal length, alternation of the dimeres is induced at the other end, and of 

 course in the succeeding elements. The length of the longer dimere is 7 "5 mm.; that 

 of the shorter, 6 '8 mm. Greatest diameter in the compression-plane is about the 

 middle of the columnal, 6'4 mm.; the corresponding diameter at the level joint-face is 



