594 Mr. II. L. Clark on the 



statement of any case, I sliall consider it a great favour to 

 be promptly corrected. 



In the tenth edition of the ' Systema Naturae ' Liniie 

 includes in his genus Echinus four nominal species {rosaceus, 

 reticulatus, placenta, orbiculus), which it is universally agreed 

 are clypeastroids. The references and figures which he cites 

 under each name show that these species, with the exception 

 of placenta, are composite groups, and not species as we 

 understand the term to-day. The form named Echinus 

 jilacenta is^ however^ a well-known East-Indian species^ and 

 there is not now and never has been any doubt as to its 

 identity. The name rosaceus has been the source of much 

 confusion, and unfortunately Loven, in his very important 

 and valuable work on the Echinoidea described by Linne 

 (1887, Bihang Kgl. Svenska Vet.-Akad. Handl. xiii.), has not 

 helped matters at all^ because, as pointed out by Lambert 

 (1905, Ann. Univ. Lyon, n. s. i. p. 142), he overlooked 

 Lamarck^s work published in 1801, which has an important 

 bearing on the matter. As Loven admits there is no 

 authentic type specimen of rosaceus, we must judge of the 

 species by what is published in the ' Systema Naturae ' ; and 

 there can be no doubt that the diagnosis and references 

 given there (ed. x. p. 665) show conclusively that the name 

 covers a composite group, including species of Echinanthus, 

 Clypeaster, and Laganum, as those genera are used by 

 A. Agassiz in the 'Revision of the Echini.' Leske (1778, 

 Add. ad Klein) failed to differentiate these various forms 

 satisfactorily, but elects to call the group Echinanthus 

 humilis, admitting at the start that his name is a synonym 

 of rosaceus. Lamarck, however, in 1801 (Syst. Anim. s. 

 Vert. p. 342), recognizing the composite nature of rosaceus, 

 restricted that name to the West-Indian species called in the 

 ' Ilevision ' Echinanthus rosaceus, and placed it as the first 

 of two species in a new genus, Clypeaster. The other species 

 {pentapora) he removed in 1816 to Scutella, and so rosaceus 

 must be the type of Clypeaster. I fully agree with Lambert 

 that Loven's attempt to restrict the name rosaceus to the 

 " species of the Eastern Seas, commonly named Clypeaster 

 placunarius," is not only unconvincing and belated, but is 

 most unfortunate. 



What, then, becomes of the name Echinanthus ? I regret 

 that I cannot answer this question in agreement with either 

 Lambert or Duncan. The reason, however, is obvious. 

 They both go back to a pre-Linnean authority. Under the 

 Code, which I am trying to follow, the fate of Echinanthus, 

 Leske, the first post-Linnean writer to use the name, is 



