Notes on Atlantic and other Asteroidea. 3. The families Ganeriidae and Asterinidae, with description of a new asterinid genus Ailsa M. Clark Department of Zoology, British Museum (Nat. Hist.), Cromwell Road, London SW7 5BD Introduction Examination of new and old material of these two closely related starfish families has prompted some additional observations on their limits and relationships, with consequent modifications to the diagnoses. A notable addition in the Ganeriidae is the abyssal genus Vemaster Bernasconi, 1965, formerly assigned to the Goniasteridae, but now shown by dis-section of new specimens to be more closely related to Ganeria, a move supported by Downey and Blake (pers. comms). Several of the nominal genera proposed by Verrill (1913) for the Asterinidae are reevaluated, resulting in the synonymy of Patiria with Asterina and, conversely, in the revival ofCallopatiria. Some recently collected asterinids from the Atlantic coast of Panama proved to represent a new genus remarkable for having many of the abactinal plates paxilliform. A difficulty arose in formally citing the type species of Asterina itself, for which a possible solution to the nomenclatural problem is given in an appendix. Systematic account Families GANERIIDAE Sladen and ASTERINIDAE Gray Blake (1981) has reviewed the history of these two families which he transferred to the order Valvatida from the Spinulosida. Briefly, Gray (1847) originally included Ganeria itself in his Asterinidae, being followed in this by Perrier (1875) and Viguier (1878). However, Sladen (1889) distinguished the subfamily Ganeriinae within the Asterinidae, on the basis of enlarged marginal plates, for Ganeria and Cycethra Bell, 1881 and this was raised to family rank by Perrier ( 1 894). Later authors, notably Fisher ( 1 9 1 1 a) and Blake (1981), have empha-sized the close affinity between the Ganeriidae and the Asterinidae. Fisher followed Sladen in distinguishing them on the basis of large size of the marginal plates in ganeriids but this does not take account of those individuals of Cycethra and all the species of the later-added Perknaster in which the marginals are reduced and the series may be barely, if at all, dis-tinguishable over part of their extent. Bernasconi (1964) and Blake (1981) have separated them on the form of the abactinal plates, with well denned columns of various height in the Ganeriidae but with ridge-like elevations or gently rounded convexities in the Asterinidae (though Blake termed both plate forms 'metapaxilliform' since the basal part of each plate is variously enlarged and the elevation often excentric) but this again does not take into account the amazing variations of Cycethra, some individuals of which have simply convex or crescentic elevations indistinguishable from those of certain Asterinidae instead of the usual well-defined but low columns ranging from circular through oval to crescentic in sec-tion. Blake also utilized the arrangement of these plates, said to be in ill-defined rows in Ganeriidae but well-defined ones in Asterinidae; however, some asterinids, especially those of large size comparable to that of many specimens of Ganeria and Cycethra, have an essen-tially alternating abactinal skeleton, though alternate plates may have a secondarily longitudinal alignment, for instance in Patiria granifera (Fig. 6, below) and Nepanthia crassa. In an attempt to assess the relationships of the various plate systems of Atlantic asteroids, Bull. Br. Mm. nat. Hist. (Zool.) 45(7): 359-380 Issued 24 November 1983 359
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