No. 506] 



NOTES AND LITERATURE 



1 L3 



ored bodies are radically different from the 

 un. Both are possibly connected with the 

 process of excretion; but why one should replace the other it is cer- 

 tainly hard to say. That the change is closely connected with the 

 age of the individual seems to me almost certain, though it must be 

 remembered that size in echinoderms is not a sure criterion of age. It 

 is interesting to note that most of the species of Ankyroderma described 



over 75" (p. 19). 



The name Trochostoma antedates Ankyroderma. but both are 

 synonyms of Cuvier's Molpadia (1817) which includes also 

 Haplodactyla Grube (not Semper), as well as the long-dis- 

 carded Embolus Selenka, and Liosoma Stimpson (not Brandt). 

 In this enlarged genus Molpadia. twenty-seven species are 

 recognized. 



Some of the more important ehaimes in the limits or names 

 of genera, as well as certain new genera, will be noted. Synapta 

 is monotypie and restricted to 8. maculata Chamisso and Eysen- 

 hardt (8. beselii authors) ; Oestergren's Chondroclcea is called 

 by the older name Synaptula; Leptosynapta Verrill is rein- 

 stated for the inhcerens group; Synapta kefersteinii is made the 

 type of a new genus Polyplectana ; the recently described 

 Opheodesoma is accepted for the Euapta glabra group; the old 

 species Chiridota rufescens is made the type of a new genus 

 Polycheira: Tamiogyrus Semper, for Chiridota australiana 

 Stimpson, is accepted as distinct from the later Trochodota Lud- 

 wig; Chiridota japanica v. Marenzeller is made the type of 

 Scolidota, new: Achirodota is founded upon Anapta inrrmis 

 Fisher, and Toxodora Verrill is reinstated. The most important 

 change in the Molpadiidae has already been noted. Haplodactyla 

 Semper 1868 (not Grube, 1810) is renamed Aphelodactyla. with 

 five species. Ceraplectana and Ilimasthlephora are two new 

 genera, the former near Molpadia, the latter related to Gephyro- 

 thuria Koehler and Vaney. 



It has occurred to the present reviewer that, had space per- 

 mitted, a very useful feature would have been the insertion of 

 a complete diagnosis under each species not described in Part 

 H. It is not possible to include in keys all the positive char- 

 acters of a species, nor is it always possible for the average 



