KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 2. 109 



(a) Crown and stem; figured Angelin, IV, 7 and 7 a. 119 Ang. 186 RM. (Pl. 

 V, fig. 148). 



(b) Upper part of a crown; 119 Ang. 186 RM. 



(c) Calyx with a few brachials; figured Angelin, IV, 7 b and 7 e, and Wachsmuth 

 and Springer, IX, 5. 187 RM. (Pl. V, fig. 156). 



(d) Calyx with a few brachials; figured Axgelin, IV, 7 c and 7 d, and Wachsmuth 

 and Springer,'iX, 1. 117 Ang. 187 RM. (Pl. V, fig. 157). 



(e) Crown minus infrabasals, with ventral tube partly preserved. (Pl. V, fig. 149). 

 (/) Crown with ventral tube. 



(c/) Crown with abnormal base. (Pl. V, figs. 150, 151). 



(h) Dorsal cup with deltoids preserved. (Pl. V, figs. 152, 153). 



(i) Ventral tube, consisting of about 20 plates. (Pl. V, figs. 154, 155). 



Descriptioii. 



Dorsal Cup is in general form conical, with its plates massive and rounded. 

 Measurements are as follows: 



In d — Height 13.5 inni. Width at base 6 inni. Width above 14.0 mm. 

 In c — 14.5 » » 7 » 15.2 » 



Speeimen a is a little smaller. 



IBB 5, equal, pentagonal as seen from outside. 



BB 5, three are hexagonal; post. and r. post. are heptagonal and niueh wider than 

 the others. 



RR 5, shield-shaped; a broad articular facet occupies almost their whole width, and 

 in sonie cases reaches almost half-way down the radial. The facet is a smooth saucer- 

 like depression: it has no axial canal, but there is a notch for the passage of the 

 axial cord. 



R' is pentagonal. It rests on the two heptagonal basals, and supports the anal x 

 on its left. r. post. R on its right, and, in between, another anal plate. 



Generally the plates of the cup are nearly as high as wide, thus giving a soinewhat 

 elongate appearance to the cup; but in some cases they are rather lower in proportion, 

 so that the cup forms a broader cone: this is shown by Angelin's figures 7 b and 7 c and 

 by the measurements of those specimens given above. 



In speeimen g the cup is abnormal. There are only two IBB, viz., ant. and 1. ant. 

 Pust. and r. post. BB are larger than the others, and combine with the two IBB to form 

 a base of 4 plates. The cup is slightly crushed, but there appears no doubt that this is 

 the correct interpretation. 



Arms dichotomous, simple; with no axial canal, and with a ventral groove of no 

 great depth. The brachials are wide and low. The ventral groove is covered by small 

 squarish or pentagonal alternating plates. 



IBr 2, rarely 1 or 3; very wide and low. Sometimea IBr, does not cover the whole 

 articular facet of the radial, but allows a part of IBr g to rest on it. In those rare cases 

 where IBi'j has wholly disappeared, IBr g , which is axillary, is so thin that it hardly sep- 

 arates the secundibrachs from the radial. 



