GENEKA AjSTD aBOUPS OP THE ECHINOIDEA. 147 



Recent. Mediterranean, Eed Sea, Indian. Ocean, Japan, Sand- 

 wich Islands, Philippines, Australian seas. 



The next genus is not a satisfactory one. 



Genus Euka, Agassiz, 1841, Monogr. d'EcJi. viv. etfoss. livr. 2, 

 Les ScuteJles, p. 32. 



Test very small, depressed, faintly arched dorsally, subcircular 

 or ovoid at the thick, deeply incised margin. 



Apical system central ; four genital pores. 



Ambulacra large, separated from the iuterradia by grooves 

 dorsally and at the margins by incisions ; petals short, widely 

 open and everted distally ; faint median groove actinally. 



Interradia small. 



Peristome circular, elliptical, central. Periproct small, between 

 the peristome and the posterior margin. 



Fossil. Tertiary : Europe. 



A. Agassiz and Llitken consider Moulin ia = MouUnsia, Agassiz, 

 1841, Monogr. d'Ech. viv. et foss. livr. 2, Les Scutelles, p. 139, 

 tab. 22, to be synonymous with Encope, the young forms of this 

 genus greatly resembling the species of Moulinsia. But if the 

 figures given by the elder Agassiz be compared with those of A. 

 Agassiz, it will be seen that there is much more general scolloping 

 of the edge of the tests than is seen in the young (supposed) 

 Encopes. E. Etheridge described a species from N. Africa which 

 he placed in a genus Motuloidea., and it shows the least possible 

 anterior lobing. Under the circumstances it is best to consider 

 Moulinsia and Hotuloidea as two closely allied genera. 



Genus Moulinsia (Moulinia), Agassiz, 1811, Monogr. d'Ech. 

 viv. etfoss. livr. 2, p. 139, tab. 22. Desor, 1848, Synopsis, 

 p. 222. Gray, 1855, Cat. Bee. Ech. Brit. Mus. p. 27. 



Test small, thin, very depressed, oval, slightly tumid above the 

 edge, but flat dorsally. Margin lobed on account of the grooves 

 along the median lines and between the ambulacra and interradia ; 

 some transverse grooving of the coronal plates. 



Apical system small, central ; five genital pores ? 



Ambulacra with petaloid parts widely open distally. 



Peristome central. Periproct inferior, between the peristome 



and the posterior margin. Ambulacral pores not united by a 



groove. Tuberculation very distinct. 



Recent . Martinique. 



10* 



