Miscellaneous. 273 



represented in the collections obtained in the West-Indian. Sea, 

 such as Zoroaster, Korethraster, and the curious genus Pedicellaster, 

 Sars — Zoroaster by two species already described by the author, 

 Korethraster by a species distinguished by the membrane which 

 unites its dorsal spines, and indicating a remarkable passage towards 

 Pteraster, Pedicellaster by a species remarkable for the arrangement 

 of its skeleton. These new species are named by the author 

 Korethraster palmatus and Pedicellaster Pourtalesi. 



Besides the new genus Hymenodiscus, already described by 

 M. Perrier, he finds several others which present intermediate 

 characters between different groups of Echiuodermata. Goniopecteti 

 in the structure of the skeleton seems to belong to the Goniasteridse; 

 but its pointed ambulacral tubes and the form of the teeth exactly 

 resemble those of Astropecten. Of this type the author distinguishes 

 four species. The Radiasteres, brought up from a depth of 1800 

 metres, are large five-rayed starfish, with tufts of spines like those 

 of Solaster, marginal plates like the Goniasteridae, and ventral plates 

 arranged in series as in some Asterinidse. The Ctenasteres, which 

 are still larger (nearly 0-3 metre in diameter) and come from a 

 depth of 3500 metres, have six arms, resemble gigantic Gtenodisci 

 destitute of ventral scales, and thus approach the Echinasteridse. 

 The Marginasteres, on the contrary, are small pentagonal Starfishes, 

 which would be taken for Asterince if they had not marginal plates 

 like those of the Goniasteridae. 



Archaster, common in all the great depths of the Atlantic, occurred 

 peculiarly abundantly. The author refers to seven species, one of 

 which. A, mirabilis, of very variable form, is represented by several 

 hundred specimens. The Goniasteridse are represented by eleven 

 species, all new, among which are several belonging to the genus 

 Dorigona, Gray. The new genus Antlienoides is intermediate be- 

 tween Anthenea, with large pedicellariae and a naked skin, and 

 Pentagonaster, with small pedicellariae and a granular skin. 



Several new forms of pedicellarias occur. Pentagonaster ternalis 

 has them with three branches. The Luidice present two, three, and 

 even four branches ; but the most remarkable are those of Archaster 

 mirabilis. Two ossicles are placed opposite each other like two 

 parentheses, and each of them has a comb of spines, forming a very 

 complex prehensile organ. The aiithor considers that this example 

 leaves no doubt as to the homology of the pedicellariae with the spines 

 or calcareous granules of the skeleton in Echinodermata. He says 

 that there is a remarkable concordance between the number of 

 tentacles, the structure of the mouth, and the form of the pedicel- 

 lariae, which would seem to indicate the division of the Astcriadae 

 into two distinct great families. From his new researches it results 

 that there is an agreement between the structure of the mouth and 

 the number of rows of ambulacral tubes, an agreement rendered 

 necessary by the relations with the mouth of the skeleton that 

 separates these tubes ; but the general structure of the skeleton and 

 the form of the pedicellariae do not accord with these data, and 

 must be regarded as furnishing more general characters. — Comptes 

 Bendus, January 10, 1881, p. 59. 



Ann. & Mag. N. Hist. Ser. 5. Vol. vii. 20 • 



