146 



SALENID^. 



has nothing in common with the spongy madreporiform body which occupies tlie surface 

 of the right anterior genital plate (PL XV, fig. 4, a, t). I had the good fortune to make 

 this discovery some years ^ ago, when figuring and describing Acrosalenia hemicidaroides, 

 which urchin has furnished a key to the true relation of the bilateral parts to the longi- 

 tudinal axis of the SALENiDiE. On this point M. Desor observes : 



" Nous devons en outre a M. Wright une autre decouverte plus iraportante, celle du 

 corps madreporiforme, qui fait partie integrante de I'une des plaques genitales corame dans 

 les autres Cidarides. Or comme nous savons maintenant que cette plaque a une position 

 fixe dans tons les oursins, nous sommes par la meme en raesure de determiner Pavant et 

 I'arriere de ces animaux ; et puisque les plaques sur-anales sont situees eu arriere de cette 

 plaque, il s'ensuit que le periprocte se trouve reellement refoule en arriere. II ne peut 

 des-lors plus etre question d'Acrosalenies a periprocte eccentrique en avant, corame on 

 supposait que c'etait le cas de \' Acrosalenia tuberculosa" &c. 



" II n'arrive que trop souvent que le disque apicial manque, et dans ce cas, il est tres 

 difficile de distinguer les Acrosalenies du genre Hemipedina decrit-ci-dessus. Cependant, 

 comme par suite du refoulement du periprocte en arriere la plaque genitale impaire ou 

 posterieure gagne plus que les autres sur le test, on peut encore, d'apres M Wright, 

 reconnaitre la place de cette plaque meme dans les individus depourvus d'appareil apicial." ' 



Family. Sections. 



Genera. 



03 C9 



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55 -72 «! 



A Table showing the Classification of the Salenid^. 



Diagnosis. 

 Ambulacral areas straight, large, with two rows of small , 

 tubercles ; apical disc small and not prominent ; sur-anal plate I Acrosalenia Ao-assiz 

 composed of one or many pieces granulated on the surface ; 

 vent posterior and central in the axis of the test ; spines long. 



Ambulacral areas narrow, flexed, with two rows of granules ; 

 apical disc prominent, not granulated, and marked with impres- 

 sions ; vent exceutral posterior, in the axis of the test ; spines I 

 '•enlarged, ovoid, sub-glandiform, more or less granular. J 



Inter-ambulacral tubercles moderate; apical disc large and] 

 prominent; genital plates in the form of elongated lobes ; sur- I 

 anal plate single ; vent posterior and central in the axis of the | 

 test. 



Pseudosalenia, Cott. 



I Peltustes, Agassiz. 



— s- 



luter-ambulacral tubercles large, few in number ; apical disc 

 large, and forming a regular pentagon, with elevated angular 1 

 carinae independent of the sutures ; sur-anal plate angular; vent <?<'«»o?^'""«*. Agassiz. 

 large, escentral, oblong, and posterior. j 



Inter-ambulacral tubercles large ; apical disc wide and very solid, 



with an undulated circumference ; surface of the large plates 



ornamented with punctuations or sculptured figures along the 



line of the sutures ; sur-anal plate single ; vent posterior ex- 



> central and directed towards the right side. 



V Salenia, Gray. 



^ Wright, 'Annals and Magazine of Natural History,' 2nd series, vol. viii, p. 261. 

 2 ' Synopsis des Echinides fossiles,' p. 140. 



