A REVIEW OF THE MYSIDACEA 177 



Outside American waters the species has a general Arctic distribu- 

 tion. The bathymetric range of the species has been increased by the 

 above records, the specimens from Albatross station 3325 being taken 

 in 284 fathoms, a greater depth than any previous record. 



Remarks. — There is a small nodular papilla on the upper surface 

 of the eyestalk and a well-developed spiniform subrostral process 

 ventral to the rostral plate of the carapace. Fully adult males of 

 this species have so far not been described. The specimen figured by 

 Sars (1879a) on his plate 42 is not quite adult and shows no brush 

 on the antennular lobe. I give herewith a figure of the third and 

 fourth pleopods (figs. 66, e, f) of an adult male with the antennular 

 brush of setae well developed. It will be seen that the general form 

 of these appendages agreed with Sars' figures (figs. 66, c, d) but that in 

 pleopod 4 the terminal joints are more elongate and the three setae at 

 the distal end are very much longer and strongly plumose. The 

 smallest adult male in the collection is 30 mm., but specimens measur- 

 ing 32 mm. are not fully mature and the size of adults reaches 33 mm. 



STILOMYSIS MAJOR, new species 



Figure 67 



Description. — This species is so similar to S. grandis (Goes) that 

 the description and figures given by Sars (1879a) for that species will 

 serve for the new one except for the following points : 



(1) The antennal scale (fig. 67, a) is much longer and narrower 

 than in S. grandis. It is at least 10 times as long as broad with the 

 apical part very slender though not actually spiniform as in the genus 

 Neomysis. In S. grandis the scale is only six times as long as broad 

 with a rounded apex (fig. 66, a) . 



(2) The telson (fig. 67, b) is relatively more attenuated than in 

 /S. grandis though actually about the same length in proportion to the 

 breadth at the base, i. e., twice as long as broad at the base. The distal 

 end is, however, relatively narrower and more pointed and the truncate 

 apex therefore smaller than in S. grandis. The lateral margins have 

 about 84 spines distributed throughout their entire length, whereas in 

 S. grandis there are about 55-60 spines (fig. 66, b) . 



(3) It is a larger species, attaining a length of 46 mm. as against 

 33 mm. for S. grandis. 



In all its other characters this new species agrees with S. grandis 

 so closely that detailed description is superfluous. It might legiti- 

 mately be regarded as merely a giant and more attenuated variety 

 of jS. grandis, but its area of known distribution is separated from 

 that of S. grandis by at least 20° of latitude, and it seems better for 

 the moment to regard it as a separate species characterized by its 

 larger size, longer and narrower antennal scale, and more slender 



