92 







secretive system; the complete resemblance of all these to the same in other star-fishes, 

 has been previously sufficiently demonstrated; for which reason it is unnecessary here again 

 to notice each one of them separately. But with respect to the generative organs, an obser- 

 vation may yet not be out of place. In the arrangement of these organs, the Brisinga appears at 

 first glance to be very remarkably distinguished from all other Asteridse; as the generative 

 organs are in the Brisinga quite separated from the disc, and limited to the arms only; 

 while in all other star-fishes they take their origin trom the disc itself, even if in some few 

 forms they also extend more or less into the cavities of the arms. This apparently very 

 anomalous case may yet be quite naturally attributed to the excessive reduction of the disc 

 in the Brisinga, which only corresponds to the central part of the disc in other star-fishes; 

 while the peripheral part of the disc in these, is in reality homologous with the basal part 

 of the arms in the Brisinga. If we admit this, it will easily appear that the organs of 

 generation (as described in the Brisinga coronata) really correspond,, not only in structure 

 but also in position, to what is normal in star-fishes generally (comp. moreover the 2 sche- 

 matic Figures 36 and 37 in Tab. VI). 



6. 



Relation of the genus Brisinga to now living slar-fishes. 



Among the now living star-fishes, the genus Brisinga seems indeed to stand rather 

 isolated, as well with regard to its exterior habitus as in respect of particular points of its 

 interior organisation. There are however certain genera of star-fishes with which it seems 

 to exhibit a closer affinity than with others. Among the better known native genera, there 

 are chiefly 2 which we may take as instances of this, namely Asterias and Solaster. The 

 former is, next to the Brisinga, that one of all our Asteridse in which the disc is the most 

 reduced relatively to the arms; and it is probably also, next to the Brisinga, that one which 

 we must regard as the oldest or least altered star-fish form, a conclusion which is comple- 

 tely corroborated by paleontological indications. The Brisinga shews affinity to the genus 

 Asterias in the form of its pedicellaries, partly also in the structure of the cuticular skele- 

 ton, and finally in the more solid composition of the interior set of vertebras (the oral ring). 

 The genus Asterias has however 4 rows of water-feet; while the Brisinga has only 2, in this 

 respect resembling the genus Pedicellaster, which was established by my Father, and 

 which in other respects is in close affinity with the genus Asterias. The Brisinga is how- 

 ever distinguished both from the Pedicellaster and Asterias (at least from our native spe- 

 cies) by its considerable number of arms or rays, in which respect again it agrees better 



