546 REV. T. R. R. STEBBING ON CRUSTACEANS [May 22, 



In regard to that species he says that the second pair of maxilla? 

 " have the terminal joint not very large, of a rather regular ovoid 

 form, and but sparingly supplied with bristles." The shape appears 

 from the figure to be rather similar to that in the present species, 

 but the size and armature very different. 



First maxillipeds to the third perseopods. — In all these ap- 

 pendages the penultimate joint is longer than the ultimate and, 

 to a less extent, than the antepenultimate, but these three joints 

 combined differ greatly in their relation to the preceding joints, 

 being at least as long as both third and fourth joints in the first 

 maxillipeds, but shorter than the fourth by itself in the third 

 perseopods. In the second and third perseopods their length is 

 absolutely as well as relatively shorter than in the preceding limbs ; 

 but also the length of the third and fourth joints successively 

 increases from the first maxillipeds onwards, and whereas in the 

 first maxillipeds and to a less extent in the second the fourth 

 joint is shorter than the third, in the following appendages it is 

 increasingly longer. The exopods of all these six pairs of 

 appendages have a close general resemblance. Sars, in describing 

 the genus, speaks of the articulation between the peduncle and 

 the flagellum as very oblique, and figures the rlagellum as un- 

 jointed. But, at least in the present species, it appears that the 

 flagellum has transverse lines of a feeble and perhaps evanescent 

 articulation, and that the junction with the peduncle is also trans- 

 verse, a strongly marked oblique line on the peduncle following 

 the course of a muscle but not constituting an articulation. Claim's 

 figures of E. mulleri seem to be in agreement with this view of 

 the matter. 



The uropods. — The rami are equal in length, and scarcely reach 

 beyond the insertion of the subapical processes of the telson. 



The telson. — The subapical processes are quite smooth. The 

 apical piece of the telson between them narrows above the middle, 

 carrying at this point two minute spinules, and then widens, 

 passing with convex margins to an acute apex. Below the middle 

 of its entire length the telson has a pair of dorsal spinules. 



Lenyth. The specimen of which the parts are figured measured 

 16 mm. Another measured 18 mm., and a third 21 mm. None 

 had sexually metamorphosed pleopods. 



Locality. Stanley Harbour, Falkland Islands. 



Gen. Thysanoessa Brandt. 



1851. Thysanoessa (subgen.), Brandt, Middendorff's Sibirische 

 Beise, Krebse, p. 52. 



1882. Thysanoessa, Sars, ChristianiaA T idensk. Borh. no. 18, p. 52. 



1883. Thysanoessa, Sars, Christiania Yidensk. Borh. no. 7, p. 25. 

 1885. Thysanoessa, Sars, 'Challenger' Schizopoda, Beports, 



vol. xiii. pp. 63, 119. 



1887. Thysanoessa, Hansen, Vid. Medd., Malac. mar. Groeul. 

 occid. p. 54. 



