A REVIEW OF THE MYSIDACEA 45 



Family MYSIDAE Dana 



Mysidae Dana, 1852b, p. 636. 



Maxillule without palp ; first thoracic limbs as a rule with a well- 

 developed exopodite ; second thoracic limbs without a lamellalike ex- 

 pansion of the merus; propodus or carpopropodus of the endopods 

 of the third to the eighth thoracic limbs as a rule divided into a number 

 of subjoints ; generally two or three, rarely seven, pairs of oostegites ; 

 pleopods of the female rudimentary, rarely biramous, generally con- 

 sisting of a small un jointed plate; pleopods of the male either well- 

 developed, biramous, natatory appendages, or one or more pairs re- 

 duced as in the female, and one or more pairs secondarily modified as 

 accessory sexual appendages ; statocyst on the inner uropods. 



Hansen in his survey of the crustacean limbs has shown that in the 

 Mysidae the carpal joint of the endopods of the thoracic limbs is 

 distinct in some forms and the propodal joint alone divided into sub- 

 joints, or in other species, the carpus and propodus are fused and 

 the fused joints divided into subjoints. 



The family is divided into six subfamilies to which Hansen ( 1910, 

 p. 11) has provided a useful key. Four of these subfamilies are repre- 

 sented in this collection, the subfamilies Ehopalophthalminae and 

 Mysidellinae being absent. 



Subfamily Boreomysinae 



Seven pairs of oostegites in the female; labrum broader than long, 

 without frontal process; endopods of the third to the eighth thoracic 

 limbs with the carpus distinct and the propodus divided into two or 

 three subjoints; pleopods of the male well developed, biramous; 

 exopod of the second and third pairs elongated ; exopod of the uropods 

 with the proximal part of the outer margin naked, and generally with 

 one or two spines and a transverse rudimentary articulation at the 

 end of the naked part ; telson distally cleft, cleft armed with teeth. 



Only one genus, Boreomysis, is included in this subfamily. About 

 20 species have been described, of which 10 are listed below. 



Genus BOREOMYSIS G. O. Sars 



Boreomysis G. O. Sars, 1869, p. 330. 



Petalophthalmus (pars) Willemoes-Suhm, 1874a, p. xv. 

 Arctomysis Czerniavsky, 1882a, pp. 61, 69 ; 1887, p. 6. 

 Pseudanchialus Catjllery, 1896, p. 368. 



I have examined the type specimen of Pseudanchialus megalolepis 

 Caullery in the Paris Museum and find that it is a specimen of Boreo- 

 mysis tridens G. O. Sars. Pseudanchialus therefore becomes a straight 

 synonym of Boreomusis. 



