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somewhat different shape from that of the Br. coronata, with a more sharply projecting 

 dorsal ridge and more vertical exterior sides. The vertebrae of the exterior set are con- 

 siderably shorter above and nearly disc-like; so that, when the oral ring is viewed from 

 above, (fig. 7) they appear like an extremely narrow rim around the strongly developed 

 interior set of vertebrae. As a consequence of this, the wedge-plates (see fig. 8) rise also 

 more perpendicularly than iii the other species. Their upper enlarged end is less tuber- 

 cularly salient, and regularly formed; and the dorsal marginal plates attached to their lower 

 extremities, stand so closely together that their exterior articulating surfaces nearly touch 

 each other. The very narrow, scarcely perceptible, fissure between the parietal plates in the 

 interior wall of the oral ring of the Br. coronata, is here (see fig. 7) widely gaping and 

 spanned over with extended soft brownish ligaments. On closer comparison of the single calca- 

 reous plates which compose the oral ring, with the corresponding plates in the Br. coronata, 

 there will likewise be found several points of dissimilarity in shape, on which however it 

 would not be expedient here to enter. The greatest difference appears to be in the interior 

 adambulacral plates. They are here (see fig. 9) much narrower, and have a very conspi- 

 cuous instriction in the vicinity of the adoral extremity, which is thus divided, as it were, by 

 a furrow of demarcation, from the rest of the adambulacral plate. 



With regard to the ambulacral skeleton of the arms (fig. 15 & 16), the individual 

 joints or vertebrae are on the whole shorter and broader than in the Br. coronata, especially 

 the interior ones; and their dorsal ridge is more regularly semicylindrical; not, as in Br. 

 coronata, distinctly enlarged at the extremities. Of the dorsal marginal plates there are 

 always 3 distinctly developed, and rudiments of 1 or 2 others (see fig. 11, 15, 16). It is 

 still more clearly to be seen here than in the Br. coronata, that the marginal plates further 

 out on the arm are in reality represented by the enlarged extremities of the calcareous 

 ribs (see fig. 11 & 13). 



As to the internal organisation, we must further notice a remarkable difference 

 between the two species of Brisinga. This remark applies to the organs of generation. 

 While in the Br. coronata they only form 2 widely ramified symmetrical organs situated in 

 the basal part of each arm, each organ with its single issue, they represent in the Br. ende- 

 cacnemos (fig. IS & 21) a great number of separate glandulous bodies, which are arranged 

 on each side of the medial line in a single row, extending to about half the length of the 

 arm. Each of these bodies has its separate issue, opening nearer to the dorsal side of the 

 arms in a fine pore. Therefore, instead of the 2 symmetrical apertures of generation in the 

 Br. coronata, we find here for each arm a double row of numerous apertures, as has already 

 been remarked by Asbjornsen. This wonderful arrangement of the generative apparatus, to 

 which nothing corresponding is found in other star-fishes, is in so far of great interest, as 

 we may see herein a characteristic of very ancient origin, an inheritance from the worm- 

 like ancestors of the Brisinga, which has still been only partially preserved in the class of 

 Crinoidse. The ovaries (see fig. 18, 19, 20) are very slightly ramified, and often appear like 



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