KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 2. 163 



Tal). XXVII, lig. 1 a does not show the riner ossicles, although the general appear- 

 ance is well rendered. 



Tab. XXVII, tigs. 1 e, /, g are supposed to be taken from a specimen of this speeies, 

 but have too many covering-plates to the ossicle (see figs. 298 — 301). 



Tab. XXIX, lig. 74 is made up from two specimens; the crown is very fairly rend- 

 ered and is magnified 5/4ths. 



Tab. XXIX, lig. 74 a represents the crown that is seen in lig. 74; the general ap- 

 pearance is fairly rendered, but the infrabasals, which are the really important part, are 

 incorrect (see lig. 294). 



Locality: Follingbo and (?) Quarry between Bara and Wallstena; bed f. Not 

 known out of Gotland. 



Gissocrinus umbilicatus. 



(Plate IX, figs. 307—315.) 

 1878 Angelin, Iconographia, p. 11, Tab. XXI, figs. 8—10, and Tab. XXIX, fig. 75 a, b. 



Diagnosis. 



Dorsal ('up low; broadlv expanding above and ben t in at the base; its plates thrown 

 into broad axial folds. IBB minute, covered by stem. BB low, at right angles to stem. 

 RR lunate, with facet 0.64 of width. IBr 2. IIBr 2. Arms braneh about 5 times. Arm- 

 ossicles with slight distal expansion and rounded backs; much compressed laterally. Ven- 

 tral Sac vertical; composed of hexagonal plates depressed at corners, which distally be- 

 come more quadrangular with transverse folds and longitudinal ridges. Stem-ossicles 

 pentagonal, alternating in height and all ridged. 



Of this speeies there are in the Riksmuseum three specimens, viz., (a) a crown, No. 

 84 Ang., original of Tab. XXI, figs. 8 and 9. (b) stem and lower part of a crown, No. 

 83 Ang., original of Tab. XXI, lig. 10 and possibly of Tab. XXIX, lig. 75 a. (c) the 

 distal part of a crown, No. 89 Ang., not drawn in Angelin's MS. 



Description. 



The general shape of the crown is something like that of G. campanula, but it is 

 less swollen and the cup is flatter. 



Dorsal cup broadly expanding and bent in at the base, so that a part of the basal 

 circlet and all the infrabasal are covered by the stem. The plates are thrown into broad 

 axial folds, being deeply impressed at their angles (ngs. 307, 308). 



IBB not distinguished, being minute and covered by the stem. 



BB 5; spreading at right angles to the stem. They are hexagonal or possibly 

 pentagonal, except post. B, which has a truncate top. Their adjacent sides are short, 



RR 5; spreading outwards and upwards. Above the facet the radial processes bend 

 in very sharply. The facet occupies 9/14ths the width of the radial. 



