108 MESSES. NORMAN AND STEBBING ON THE 



Uropods biramous; inner branch 4-5-jointed, outer minute, 



but distinctly 2-jointed Heterotanais, G. O. Sars. - 



(d) Upper antennse conical, 3-jointed, and with a rudimentary 

 flagellum in female, much more elongated and with a 

 multiarticulate flagellum furnished with fascicles of sensi- 

 tive cilia in male. Gnathopods in female strong, of the 

 usual form ; in male greatly elongated ; hand very large, 

 oblong, with elongated, curved, forcipiform fingers, the 

 immovable one tuberculated on inner margin. Uropods 

 2-branched, inner branch multiarticulate, outer very small 

 and rudimentary, consisting of only a single joint . . . Leptochelia, Dana. 



For full accounts of the foregoing genera, and especially for descriptions of the 

 mandibles, which afford valuable diagnostic characters, reference should be made to 

 Sars's Monograph. 



The following is a list of all the species of this family which have, up to the present 

 time, been discovered in the North Atlantic, under which title we include that portion 

 of the ocean and its seas which lies north of lat. 35° N. : — 



List o/Tanaidae of the North Atlantic. 



Genus 1. Tanais, M. -Edwards, =Crossurus, H. Rathke. 



1. Tanais vittatus (Rathke) ,= Tanais tomentosus, Kroyer. 



Hab. Britain; Denmark; Norway; N.E.America. 



2. T. cavolinii, M.-Edw. 



Hab. Mediterranean and Adriatic. 



3. T. dulongii (Audouin). 



Hab. Britain ; Mediterranean. 



Genus 2. Leptochelia, Dana. 



1. Leptochelia savignii (Kroyer), = Tanais edwardsii, Kroyer, $ , = Leptocheliaalgicola, Harger. 



Hab. Britain; Mediterranean; Madeira. 



2. L. neapolitana, G. O. Sars. 



Hab. Naples. 



3. L. rapaw, Harger. 



Hab. N.E. America. 



4. L. ? Jilum (Stimpson). 



Hab. N.E. America. 



5. L. dubia (Kroyer), =Leptochelia algicola, Harger. 



Hab. Mediterranean; N.E.America; Brazil. 



Genus 3. Alaotanais, Norman & Stebbing. 



1. Alaotanais serratispinosus, Norman & Stebbing. 

 Hab. North Atlantic ; abyssal. 



