HOO TAilK SKOCiSBEiyi 



Entoinuconclnts M'('()^, lonu u special family, Entomocunchidae, by the side of the famihes 

 CyprkUnidae and ,,Conchueciadae'' within the section Myodocopa. G. S. BRADY and A. M. 

 Norman, in their work of 1896, p. 628, write of this genus that it ,, probably will be found to 

 belong to the group Myodocopa''. When in 1902 a, p. 188 G. S. BRADY established the genus 

 Codonocera he wrote the genus Heterodesmus as a synonym: ,,? Heterodesmus BRADY." Since 

 then — if we are to judge from the literature — this form has never been foimd again, nor have 

 any new species been described that can be referred with certainty to this genus. 



On account of the incompleteness of the description G. W. Muller, when revising the 

 Ostracod group, did not think it possible to place this genus systematically. In his synoptic 

 work of 1912, p. 398 he puts it under the heading of ,,0 s t r a c o d u m genera e t species 

 i n c e r t a e s e d i s"; in doing so he wished to point out that it is even impossible to decide 

 which main group within the Ostracoda this genus belongs to. Other authors who deal with 

 this group do not touch upon this genus. 



Even from the shape of the shell — the strongly ventricose ventral margin and the 

 presence of a rostral incisur (the latter is, however, only very indistinctly indicated in the figure 

 and is not mentioned in the text) — it seems very probable that the genus Heterodesmus is to be 

 placed within the group Myodocopa, as G. 8. BRADY has already done. The fact that the species 

 in question was caught swimming freely in the sea, ,, taken in the towing-net", also supports 

 this supposition. It also seems to me very j^i'obable that this genus is closely connected 

 with the sub-genus Siphonostra established by me above. This is supported, above all, by the 

 fact that, to judge from figs. 6a, g and li, H. Adamsi has a shell that is developed postero- 

 dorsally into a siphon (presumably) of quite the same type as that of the last-mentioned 

 sub-genus. The hinge of the shell points to the same conclusion. The question as to whether 

 the two forms are distinguished fi'om each other generically or not can, of course, not yet be 

 decided, though it does not seem impossible that at some future time it will appear that they 

 ought to be included in the same sub-genus. 



With regard to G. S. Brady's assumption that Heterodesmus is a synonym of the genus 

 Codonocera I may merely point out here tliat — to judge from the literature — the shell of th 

 latter gentis is not developed as a sijihon posteriorly. 



Siphonostra spinifera n. sp. 



Description: — Female: — 



Shell: — Length, 2,32 mm. Length: height, about 1,8 : 1; length : breadth, about 

 1,75 : 1. Seen from the side (fig. 3) it is very elongated with the greatest height at 

 about a, third of the distance along the shell; the anterior part is slightly larger than the posterioi' 

 one. The dorsal and ventral margins are of about the same shape, uniformly arched, the 

 arcuation is moderately strong; they join the anterior and posterior margins without corners. 

 The posterior part of the shell is, at about half the height of the shell, drawn out into a rather 

 wide process cut abruptly off distally and directed obli((uely upwards; the ventral nuirgin of 



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