studies on marine Ostracods 



Conchoecia obtusata, C. H. Ostenfeld, 1906, p. 96. 



V. VAvRA, 1906, p. 36; pi. I, figs. 13—19. 

 E. KOEFOED, 1907, pp. 150, 151, 156, 202. 



C. H. Ostenfeld and C. WESENBERc-LUiND, 1909, p. 113. 



C. APSTEIN, 1911, p. 166; pi. XXIII. 

 E. JORGENSEN, 1912, pp. 14, 16. 

 G. W. MUller, 1912, p. 74. 

 K. Stephensen, 1913, p. 3.54. 



641 



Description: — See G. W. MOller, 1901, p. 5, figs. 8—10 and V. VAvra, 1906, p. 36; 

 pi. I, figs. 13—19. 



Supplementary description. — Male: — 



Shell: — Length: According to G. W. MtlLLER, 1901 and 1912, 1,1—1,2 mm.; 

 according to V. VA\t.a, 1,2 mm. The specimens investigated by me measured 1,15 — 1,35 mm. 

 Length : height about 2:1; length : breadth about 2,5 : 1. Seen from the side it 

 is of about the type reproduced by G. W. Mtll.I.ER, 1901, fig. 8; in most cases, however, it has 

 a straighter dorsal margin and the anterior part of the shell dominates somewhat less over 

 the posterior part; cf. the accompanying fig. 1. Seen from below (fig. 3) it has its 

 greatest width at or in most cases somewhat behind the middle. Its side contours are either 

 rather evenly curved or else they are somewhat flattened at the middle. The posterior part 

 of the shell, which sometimes dominates at least to some extent, though only rather shghtly, 

 over the anterior part, is somewhat pointed, the anterior part is somewhat more roimded and 

 has an almost symmetrical rostrum. The shoulder vault is moderately well developed and well 

 rounded. The surface of the shell is almost or quite bare. Sculpture: There is a weak concentric 

 striation, in most cases rather difficult to observe. Seen from inside: Selvage: On the 

 rostrum it either has an even edge or else it is irregularly serrulated. Along the anterior margin 

 of the shell and the anterior part of the ventral margin it has in most cases an exceedingly fine 

 serrulation; along the posterior part of the ventral margin it has a fine serrulation; the serrulation 

 within the posterior margin of the shell is most frequently rather sparse. The part on the rostrum 

 has no long bristle-like process. The unsymmetrical glands have their exits at the usual place. 

 There are no lateral corner glands. Ventrally of the incisur there emerge some glands, which 

 are small or large according to the physiological condition; cf. V. VAvra, 1906, pi. I, fig. 12. 

 The medial glands along the posterior margin of the shell are moderately large; theii exits arc 

 always simple, arranged in a rather distinct row running a short distance inside the niargiu of 

 the shell and not joined by any distinct list. The jimctiou between the lamellae is rather wide 

 at the rostral incisur; dorsally of the incisur the lamellae are joined at a rather large rounded 

 part; cf. the accompanying fig. 1. At the posterior dorsal corner of the shell there is a rather 

 well developed hinge-socket and hinge-tooth of an oblong oval shape. 



First antenna: — - The b-, d- and e-bristles are either subequal or else the e-bristle 

 is somewhat longer than the two others; they are about one and a third or t)ne and a half times 



Zoolog. bidrav, U|>|Mula. Suppl.-Bd. I. ^1 



