38 OLAF HOLTEDAHL. [SEC. ARCT. EXP. FRAM 



at about the middle of tlie antero-dorsal quarter or slightly higher. Mus- 

 cular spot easily observed when the shell-substance is removed; it is 

 situated a little downwards and backwards from the eye, shows an oval 

 outline (in a large specimen the greatest diameter is about 1 mm.) and 

 an ornamentation of fine punctae. Finely anastomosing lines run from 

 this muscular spot towards the ventral and posterior margins. 



The form here described is especially characterized by its oblong 

 form in combination with a symmetrical outline, the anterior and post- 

 erior margins curving equally strongly. 



A form that I first thought was very like this one is the Leper- 

 ditia baltica Hisinger, var. arctica Salter, described from Arctic ma- 

 terials in the Appendix to Sutherland's report, p. 221, pi. 5, fig. 13, 

 judging from the illustration given there. Professor R. Jones, however, 

 later on in "Annals and Magazine of Natural History" for February 1856 

 gave a new description and new illustrations of this form (see p. 87, 

 pi. 7, figs. 1—5) and from these it is evident that the two forms are 

 quite different, the right valve of Leperditia arctica strongly projecting 

 downwards, giving a more triangular outline. 



Occurrence: B, lower part. Reindeer Valley. B, upper part, 

 near the fragment-limestone. Valley south of Borgen. 



Leperditia sp. 



A not quite complete left valve of a medium-sized ostracod may 

 probably be referred to a Leperditia. The outline is decidedly oblong 

 (reminds much of a Bythocypris), the length being 3.8 mm., the height 

 only 1.8. The dorsal margin is straight, the ventral — not fully pre- 

 served, — a little rounded. The valve is highly convex, with the most 

 elevated portion a little in front of the centre. A slightly marked 

 marginal rim can be seen at the anterior and posterior margins. The 

 surface is completely smooth, without any visible ocular or muscular spot. 



The shell is well characterised by its extremely oblong form and 

 great convexity. I know of no ostracod of the same size approaching it. 

 The nearest are some carboniferous forms from Great Britain, Leper- 

 ditia oblonga Jones a. Kirkry and L. parallela J. a. K. (see Annals 

 and Mag. Nat. Hist., Ser. 3, vol. 15, 1865, p. 407) but they do not 

 entirely agree. 



Occurrence: B, uppert part, point north of the Beautiful Valley. 



