431 



Ofversigt af Kongl. Vetenskaps-Akademiens Förhandlingar, 1867. N:o 5. 



Om Leskia mirabilis Gray. 

 Af S. LovÉN. 



[Meddeladt den 8 Maj 1867.] 



J. E. Gray beskref är 1851 detta nya slägte med följande 

 ord:*) 



"Shell ovate, subglobose, thin, vertex central; lateral ambulacra 

 broad, petaloid, rather siinken and separate from eacb. other, tlie 

 hinder lateral pair rather the shortest, the odd anterior ambulacra 

 in a rather broad siinken groove, rudimentary, with only a single 

 series of pores on each side; all surrounded by a broad, rather 

 sinuous peripetalous fasciole; lateral and subanal fasciole none; mouth 

 anterior, round, on a level with the rounded under surface, and 

 covered with five triangulär converging valves; plastron and subanal 

 plate not distinctly defined; anus round, in the upper part of the 

 rounded posterior end, and covered with five triangulär converging 

 valves forming a cone, with some small spicula in the centre; ova- 

 rian pores two, very large; spines and tubercles subequal, subulate, 

 those of the back being rather the largest. 



This genus agrees with Brissus in the form of the peripetalous 

 fasciole, but differs from it and all the other Spatangidge in the 

 form of the mouth and vent. 



1. Leskia mirabilis. Shell ovate subglobose. 

 Hab. Isle of Luzon." 



Något sednare tillägger han:**) 



"In the form of the mouth and vent it has considerable affinity 

 with the fossil Cystidea of Von Buch, as especially the genus Echino- 

 sphrerites." 



Den närmare granskning af detta sällsynta djur, och den 



jemförelse af dess munnbyggnad med den hos vissa Cystideer jag 



varit i tillfälle att företaga, bekräfta den så högst egendomliga 



*) Annals of Natural History, second series, VII, p. 134. 



**) Catalogue of the recent Echinidai or sea eggs in the coliection of the british 

 Museum, 1855, p. "63, t. 4, f. 4. 



