Marine Copepoda 11k 



of the hook; a right lateral comb-like group of strong spinules near the middle 

 of the segment and a left postero-lateral group of much smaller spinules near 

 the posterior end of the segment; also right and left dorso-lateral tufts in the 

 anterior region. The segment itself and the groups of spinules are asymmetrical. 



8. Limnocalanus grimaldii (J. de Guerne, 1886). 



This noteworthy species occurred in one gathering only, at station 27 

 t, u, Collinson point, Alaska, October 4 and 5, 1913, forming 10 per cent of 

 the copepod content (table IV) . The lateral edges of the last thoracic segment 

 (Th5) have an acute point set in the middle of the border and do not taper to 

 the point; total length of female 2-85 mm. The caudal furca is long, two-fifths 

 the total length of the urosome; the upper and lower surfaces of the caudal rami 

 are beset with short spines, the inner and outer surfaces are setulose (or 

 "ciliated"). Abdomen of female three-jointed; of male five-jointed, with spines 

 on dorsal and ventral borders of Ab 2, 3, and 4. Right geniculate antenna of 

 mal^ with five joints beyond the bend, the first of which is long, the last very 

 small. 



It has perhaps the most remarkable distribution of any marine copepod. 

 It was first taken in the Gulf of Finland and named in honour of Prince Albert 

 of Monaco by J. de Guerne in 1886. Two years later it was declared by Nord- 

 quist^ to be identical with Limnocalanus macrurus G. 0. Sars 1862 from the 

 Scandinavian lakes. Its validity as a species distinct from the freshwater form 

 was proved by G. 0. Sars who found it in material from the Caspian Sea, where 

 it constitutes part of the relict glacial fauna of that basin. ^ 



The same species (L. grimaldii) was recorded by Sars living pelagically 

 in the estuary of the river J ana in Siberia. The length of female examples 

 from Siberia was 3.30 mm., as against 2-80 mm. from the Caspian Sea. The 

 largest individual observed by Nordquist in the Baltic was 3-15 mm. long. 

 Sars regards it as a true Arctic form of marine origin and "its occurrence in the 

 Baltic and in the Caspian sea must be explained by a direct connection in former 

 times of these basins with the Glacial sea."^ 



There is a slight difference apparent between the figures of the falciform 

 process at the end of the outer ramus of the right fifth foot of the male, given 

 by Sars for L. grimaldii (1897 op. cit.) and for L. macrurus in his Crustacea of 

 Norway, vol. IV Copepoda-Calanoida, Part VII and VIII, pi. 55, Bergen 1902. 

 According to these figures the process is broader and shorter in grimaldii than 

 in macrurus. The examples of grimaldii from Alaska agree in this respect with 

 macrurus. There is a prominent ental cone on the first basal joint of the left 

 p 5 cf, corresponding with fair approximation to that indicated in the figure by 

 Sars, 1897, op. cit., pi. 4, f. 18. 



9. Eurytemora gracilis (Sars). 

 Temorella gracilis Sars (Jana Expedition, op. cit., 1898, p. 336). 



This species was originally taken in the lower part of the river Jana, in the 

 same locality as Limnocalanus grimaldii. A single damaged female, referred 

 tentatively to E. gracilis, occurred in the gathering from station 21 d, e, f, lat. 

 68° 41' N., 165° 10' W., temperature 45-5° F., August 16, 1913, surface. The 



1 Oscar Nordquist: Die Calaniden Finlands. Bidrag till Kannedom af Finlands Natur ooh Folk, 

 vol. 47, pp. 191-275, 10 pis. Helsingfors 1888. 



2 G. O. Sars. Pelagic Entomostraca of the Caspian Sea. Annuaire du Mus§e Zool. de I'Acad. Imp. 

 des Sciences de St. Petersbourg 1897, pp. 38 to 49 of the reprint which I owe to the courtesy of the author. 



' G. O. Sars: The Cladocera, Copepoda and Ostracoda of the Jana Expedition. Annuaire Mus. 

 Zool. St. Petersbourg, III, 1898, p. 335. 



