9 



Schodler (Zur Naturgeschichte der Daphniden, 1877, p. 24) is 

 very positive in his statements that the variety " fronte cornuto " 

 is a distinct species. All the specimens which I have seen want 

 the horn. 



P. E. M tiller says of the genus, of which he has seen only this 

 species, "Antennas immobiles." So Lieven, " Die Tastantennen 

 kommen mit denen dieser Art. (D. pulex) uberein." Other au- 

 thors are silent on the subject, though it might possibly be in- 

 ferred from Fischer's figures that he considered the antennules to 

 be movable. They are always free in the specimens which I 

 have seen. The correspondence in other respects with S. mucro- 

 nata is so great that I do not Like to make this a new species. It 

 is, at least, a marked variety, to which the name "fusca" might 

 be appropriately applied. 



My specimens have all the different markings which, in differ- 

 ent European localities, are considered characteristic of the spe- 

 cies. Thus Miiller says, u Areis hexagonalibus reticulata." 

 Schodler says : " Eine reticulirte Cuticula ist nur auf dem Kopfe, 

 namentlich um den Riissel herum, deutlich wahrzunehmen : der 

 Schalenklappen entbehren derselben, sind aber in der vorderen 

 Partie leistenartig gestreift. Diese Leisten verlaufen in ziemlich 

 gleicher Richtung mit dem Vorderande, und gehen, namentlich 

 gegen den Unterrand, mehrfach in einander iiber. Die Mitte der 

 Schalenklappen aber lasst nur eine feinkornige Cuticula unter- 

 scheiden." I have seen specimens from the same pool which ex- 

 hibited markings agreeing with both these descriptions, and other 

 specimens which showed still other variations. 



SPECIES 2. 

 Plate I. Figs. 8, 9, 10, 10a. 



SCAPHOLEBERIS NASUTA. sp. nov. 

 Length, circ. 1 rani. 



Rostrum pointed, antennules large and movable. Shell of 

 valves covered with pointed elevations. 



The head is separated from the body by a marked depression. 

 The lower margin of the head is slightly concave. The rostrum 



H> 



