203 



the posterior end of the plates there are three small holes of equal 

 size. The miliary granules are nearly quite dissolved circles of 

 minute granules. 



Synaptula violacea is an easily recognizeable species, distinctly 

 separated from the other known species, by its size and colour. 



Leptosynapta Verrill. 



Leptosynapta Verrill. 1867. On the geographical distribution of the 



Echinoderms of the west coast of America, pag. 325. 

 Synapta. 0stergren. 1893. Das System der Synaptiden. p. 114. 



„ Clark. 1901. The Synaptas of the New England coast, pag. 21. 

 Leptosynapta. Clark. 1908. The Apodous Holothurians. pag. 86. 

 Genotype: Synapta tenuis Ayres. 



This genus was proposed in 1867 by Verrill (Op. cit. pag. 325; 

 the footnote) for "such species as 5". tenuis Ayres of New England 

 and 5. inhaerens of Europe" and he furthermore writes that "S. 

 tenuis may be regarded as the type". In spite of this the genus 

 Leptosynapta was for more than thirty years regarded as invalid, 

 and the two mentioned species for this reason referred to Synapta. 

 As 0stergren in 1898, divided the old genus Synapta into dif- 

 ferent independent genera, he used the name Synapta for that genus 

 of which inhaerens was the typical species. In "The Apodous Holo- 

 thurians", Clark shows that the name Synapta must be used for 

 the genus of which maculata Chamisso & Eysenhardt is the type, 

 and that 0stergren's genus Synapta is identical with Verr ill's 

 Leptosynapta, which name then must be used. 



In discussing this question, Clark has no doubt that inhaerens 

 O. F. Müller is the genotype for Leptosynapta, as he is quite con- 

 vinced that inhaerens is a circumpolar species, common at the Ameri- 

 can coasts, and that tenuis Ayres is synonymous with it. In "The 

 Synaptas of the New England coast" he writes: "The common white 

 Synapta of the New England coast is S. inhaerens (O. F. Müller)" 

 and "S. girardii Pourt. and 5. tenuis Ayres are synonyms of that 

 species". The examination of the American specimens of Lepto- 

 synapta in Dr. Morten sen's large collection, shows that inhaerens 

 is not represented among them. This does not agree with the fact 

 that inhaerens is reported from numerous American localities, and 

 leads to the suggestion that the American specimens do not really 

 belong to inhaerens. In order to have this question solved, some 



