studies on marine Ostracods 437 



111 G. 8. Bhadv'.s wuiks 1868 a and 1868 b, on the other hand, some, though only minor, 

 advances are noticeable. The descriptions and reproductions of the limbs certainly leave much 

 to be desired, but the autlujr is somewhat more fortunate than his predecessors in interpreting 

 them. The first and second antennae, the mandible and the maxilla are explained correctly 

 and the seventh limb is called the ,,oviferous foot"; the fifth and sixth limbs, of which a parti- 

 cularly misleading figure is added (1868 b, pi. 41, figs, f, g), are, however, incorrectly explained; 

 their relative positions have been inverted and they are called the third and the second maxilla 

 respectively. 



After all these mistakes, due, of course, to the smaUness of the object and the curious 

 type and very concentrated position of the limbs, G. 0. Sars, 1869, pp. 358 — 359, gives in the 

 diagnosis of Asterope norvegica the first correct explanation of all the limbs; the description of 

 these organs is, however, rather incomplete, nor is it illustrated by any figures. 



Fritz Muller's essay ,,B e m e r k u n g e n ii b e r Cypridina'' also denotes an advance 

 in some respects. The rod-shaped organ is discussed, its capacity as a sensory organ is verified 

 (cf. p. 164 above); the number and the nature of the gills is established (the occurrence of gills 

 in forms belonging to this group was mentioned cursorily by this author as early as 1864, p. 73); 

 contributions are made to our knowledge about the heart and the circulation of the blood 

 (the occurrence of the heart in these forms was observed cursorily by this author as early as 

 1864, p. 72; cf. p. 164 above). With regard to the middle limbs, however, F. MCLLER gives 

 no information at all ,,um die Zahl der nur muthmaBlichen Deutungen nicht uni noch eine zu 

 vermehren". 



Our knowledge of this family has subsequently been very considerably increased, especially 

 by C. Claus's work of 1876, G. 0. Sars's, 1887 and G. W. Ml'ller's, 1894. 



As early as 1865 G. 0. Sars points out (p. 101) that the species described by \\. Baiku The daxsi/icaiiun ../ 

 under the name of Cypridina Adamsi seems to form ,,en distinct Slaegtstyp", — a distinct „„' ''].'"""'■''. 



•^^ o . IT ' ] i,g dn'ision into 



genus type — closely related to the genus Asterope. natural groups. 



In his large monograph of 1894 G. W. MCller states (p. 218) that the then known 

 forms of the genus Asterope s. 1. may be divided into natural groups; an attempt at such 

 a division was also made, but the groups that were set up received no special names. In the 

 first group there were placed Lobiancoi, G. W. MtiLl.ER, 1894, hrevis, G. W. MOller, 1890 and 

 americana, G. W. Muller. 1890; they were characterized by their short, rounded shells, the 

 uniting of the fifth anil sixth joints of the first antenna and by their short, strong main claws, 

 always few in number (three or four) on the furca. Agassizi (Fr. MCller, 1870) and fusca, 

 G. W. MULUil{, 1890 were to form one group; these two forms were characterized by lists running 

 in the same direction on the surface of the shell, by the uniting of the sixth, seventh and eighth 

 joints of the first antenna, by the small number of sensorial filaments on the sensory bristle 

 of the fifth joint on this limb in the female and by the fact that the furca has only three slender 

 and rather long main claws. Of tlie other species oblonga (K. GliL I'.E. 1859), elliptica. 

 A. rilUJlM'l. 1840 and teres (A. iM. NuR.MAN, 1861) would be closely related to each other; they 

 were characterized by the fact that the fifth, sixth and seventh joints on the first antenna are 

 free and by having six main daws mi the furca. G. W. MCller assumed that norcegica, 



