16 



OSCAR SUND 



(REP. OF THE "MICHAEL SARS" NORTH 



19 



Figs. 19 — 20. 5. splendens. 19) Rostrum of 4 specimens, the sizes 



(C) of which are inscribed, from st. 53, 1 sn 100. 20) Head and 



uropod of © 3.15 from st. 67, 1 sn 50. 



Fig. 21. S. splendens. Tip of telson of 4 specimens"' (the size of 

 which are inscribed) from st. 64 and 67. 



size. Now both S. splendens and S. grandis carry only 

 one pair of spines on the telson, as does the larger of 

 the larvae in question. But these spines in S. grandis 

 are situated very far from the tip, whereas in S. splendens 

 they are found close to it (see fig. 21). 



The larvae referred to S. splendens, were taken on 

 the following occasions: 

 St. 64, lsn 100 m.w, one, C = 2-6, L = 6-15, 



Urop. = 1-25 mm. 

 „ „ y 2000 „ one, C = 2-9, L = 7-0, 



Urop. = 1-50 „ 

 „ 67, lsn 50 „ one, C = 3-15 L = 8-7, 



Urop. = 1-70 „ 

 PI. II, figs. 2 and 3, are photos of the head parts 

 and tail-fan in the smallest of the specimens. 



Sergestes grandis n. sp. 



This species is very nearly related to the species 

 described by Faxon (1895) from the Pacific under the 

 name of S. blsculatus Wood-Mason. In 1893 Faxon had 

 mentioned his species under the name of S. phorcus, which 

 was withdrawn by himself as a synonym. Now after the 

 publication of a more detailed account with illustrations 

 of S. blsculatus by Alcock in 1901 it appears beyond 

 doubt that Faxons species is not identical with that of 

 Wood-Mason, so that the former must retain the original 

 name of S. phorcus. In describing S. grandis I shall try to 

 indicate the points in which it differs from the species 

 mentioned. 



Figs. 22 and 23 show two females, one adult and 

 one young. The relative length of carapace and ab- 

 domen is nearly as in Faxon's species, the abdomen, 

 telson excluded, equalling about twice the length of the 

 carapace, while i Wood-Mason's species, according to 

 Alcock's figure (Illustr. . . . Investigator, pi. L), the cara- 

 pace is half the length of the abdomen, telson included. 



The rostrum, as in Faxon's species, is small, inclined 

 about 30° from the back. Both edges are parallel, and 

 the tip is excavated as in S. splendens. 



Both transverse grooves are well defined, as are also 

 the gastrohepatic and the branchiocardial, the last running 

 nearly to the edge of the carapace, accompanied by a 

 marked keel. 



The branchial formula is the same as i Faxon's 

 species; the second lamella above the third leg is not 

 however concealed beneath the first, but plainly visible, 

 and it is about -/-i as long as the first. 



The eyes are as in S. phorcus. In the smaller spec- 

 imens the lateral length of the cornea is less than half 

 that of the stalk, while in the adult it is about two-thirds. 



