160 



tideopsis rostrata, G. 0. Sars, n. sp. 



(Suppl. Pi. IV & V). 



Sfteeifie Ckaraeters. Female. Body moderately slender, with the integu- 

 ments of an unusually firm consistency. Anterior division, seen dorsally. ohlong 

 oval in form, greatest width slightly exceeding l /s of the length, anterior extremity 

 conspicuously dilated in the oral region, and abruptly contracted in front, tip 

 triangularly produced, posterior extremity gradually attenuated. tVphalosome 

 separated above from the 1st pedigerous segment by a well-marked transverse groove, 

 dorsal face only slightly vaulted, lateral edges conspicuously insinuated in the middle. 

 Rostrum highly chitinized and pointing straight downwards, lateral spikes acutely 

 pointed and somewhat divergent. Last segment of metasome very short, but de- 

 tined in front by a well-marked curved suture, lateral corners produced to strong 

 mucroniform processes pointing straight backwards and extending beyond the 

 middle of the genital segment. Length of urosome scarcely exceeding l / s that of 

 the anterior division, genital segment not very large, and but slightly protuberant 

 below. Caudal rami about the length of the anal segment, and somewhat flat- 

 tened, tip obliquely rounded. Eye apparently well developed. Anterior antenna 1 , 

 when reflexed, reaching about to the end of the i j nd caudal segment. Posterior 

 antenna> with the outer ramus somewhat longer than the inner. Posterior maxil- 

 lipeds almost exactly as in ChiriiHttf. the 2nd basal joint being very narrow and 

 elongated, whereas the terminal part is comparatively short, scarcely half as long 

 as this joint. Apical spine of outer ramus in 2nd to 4th pairs of legs very 

 strong, its outer edge densely aculeate in a pectinate manner. 



Mule unknown. 



Colour not yet ascertained. 



Length of adult female 4.40 nun. 



Kcnm rkf. This form, as stated above, somewhat recalls J\ti<Ieux iirnut- 

 tnti by the strongly-developed, bifurcate rostrum and the acutely produced lateral 

 corners of the last segment of the metasome. It may, however, be at once dis- 

 tinguished by the far less vaulted cephalosorae, and the sharply marked boundary 

 between the last 2 segments of the metasome. It is also of considerably larger si/e. 



On-unmet: -Two female specimens of this form were found in a plankton- 

 sample taken, during the cruise of the "Michael Sars'' in 1900, at Stat. 34, situated 

 between Jan Mayen and Finmark. the depth being recorded to be from ."soo to 

 1000 metres. 



