Prof. F. J. Bell on the Lasranidae. 133 



mention of tlie name of Dujardin, and as his genus is distinctly 

 stated to have been established u independently," that some 

 other work than their well-known compilation was being re- 

 ferred to, were it not that that work is referred to by Mr. 

 Agassiz in his synonymy, and that Hup^'s independent con- 

 tribution to echinology (in * Amer. du Sud/ Castclnau) does 

 not contain any new genus allied to Laganum. 



Desor alone remains ; and it will be of interest to see 

 on what characters that distinguished naturalist based his 

 genus Rumphia *. 



" Grands oursins plats, plus ou moins renfles au sommet, 

 amincis vers le bord. Quatre pores genitaux. Petales 

 allonges, effiles, jamais fermes. Zones porifferes sensiblement 

 plus etroites que la zone interporifere. Face inf&rieure 

 plate. Peristome petit, k fleur du test, entoure d'une etoile 

 peristomale distincte et de cinq tubes buccaux. Periprocte 

 rapproche du bord. Point de cloisons a Pinterieur. Cinq 

 auricules au lieu de dix, comme chez les Clypeastres." 



The type of the species is Laganum rostratum ; and, so far 

 from Desor having selected a form in which the genital pores 

 occupy an extrapetaloid position, we find the sentence to run 

 thus : — u Nous envisageons comme type dece genre le R. ros- 

 trata [Laganum rostratum, Agass.). Peut-etre conviendrait-il 

 de faire egalement du Laganum Peronii le type d'un nouveau 

 genre. C'est une question sur laquelle nous reviendrons 

 en traitant des oursins vivants." 



Unfortunately for the study of the Echinoidea, M. Desor 

 does not seem to have ever carried out this intention. It 



would seem therefore to be more in consonance with the 

 facts known to us to say rather that Desor " hinted at the 

 probable generic separation of L. Peronii from Laganum" 

 than that he ever made a genus equivalent to Peronella. And 

 this view is supported by the fact that the only fossil form 

 ascribed by Desor to this genus is the species figured by 

 Herklots and called by him Scutella decagona, a form which 

 is, as we learn from Dr. Martin, " undoubtedly identical " 

 with what Agassiz calls Peronella decagonalis f. 



In other words, Desor no more than Gray, Miehelin, or 

 Hupe formed a genus for the reception of L. Peronii) or, yet 

 in other words, the utmost that any of these naturalists has 

 done has been to hint, as did Desor, at the " probable generic 



* Synopsis des Echinides fossiles, p. 229. 



t See tne important and valuable " Kevision of the Fossil Echini from 

 the Tertiary Strata of Java n (in Notes Leyd. Mas. ii. p. 78), by Dr. K. 

 Martin. 



