77 



Munida tenuimana, G. O. Sars. 



PI. XI, figs. 15-16. 



Munida tenuimana, G. O. Sars, 1871. 

 Munida tenuimana, G. O. Sars, 1882. 

 Munida tenuimana, Appellof, 1906. 

 Munida tenuimana, Hansen, 1908. 



This species is very closely allied to M. bamffica, but it is 

 separable from the latter by certain well-marked characters. 



Appellof (1906) gives the following summary of its characters : 



" Eye-bulb broader than in M, rugosa ( =bamfflca) ; circlet of 

 hairs quite rudimentary or altogether absent ; spines always 

 present on the middle part of hind margin of carapace ; two 

 spines on fourth abdominal segment ; dorsal surface of abdominal 

 segments with 6-7 furrows ; limbs slenderer than in rugosa 

 ( =bamffica).''^ 



All these characters are reliable, but Hansen points out that 

 Appellof has not observed the best distinguishing mark, viz., 

 the surface of the sternal plates. He says : " In both species 

 the sternum is divided into four segments by raised cross-lines 

 furnished with marginal hairs. In M. bamffica it is further, 

 as if covered with scales almost everywhere, which is due to 

 the presence of numerous large and small, slightly -arched 

 tubercles, the convex, anterior, or outer margin of which is 

 well marked off and provided with hairs. ... In M. tenuimana 

 the sternum is very shining and without the scale-formations 

 as in M. bamffica ; there are some rows of bristles on a part of the 

 first sternal segment, but the scale-like tubercles are rudimentary, 

 and as a rule the second, third, and fourth segments are smooth, 

 with altogether extremely few short rows of hairs, chiefly out 

 towards the lateral margins ; sometimes, also, we meet with a 

 small number of such rows scattered over the surface of the 

 segments, but the scale-formation, i.e., the raised, seemingly 

 imbricate areas are never developed." 



M. tenuimana is, on the whole, more slightly built than M. 

 bamffica ; the carapace is not quite so broad, and its margins 

 are not so convex as in the latter species. The pereiopods, and 

 in particular the first pair, are longer and more slender. 



The circlet of hairs round the eye is almost entirely absent, 

 and in some specimens completely so. The eyes are usually 

 slightly larger than in bamffica. The sternum is as described by 

 Hansen in all the specimens taken by the Helga. In some cases 

 there are a few hair-fringed ridges on the second and third 

 plates, but otherwise they are absent except near the anterior 

 edge of the first sternal plate. In all the specimens of bamffica, 

 on the contrary, the sternum is covered throughout with curved 

 ridges and tubercles. 



In all the specimens which I have examined the supra-orbital 

 spines are elevated at a greater angle than they are in bamffica, 

 in which, indeed, they lie almost in the same plane as the rostrum. 



