246 SPOLIA ZEYLANTCA. 



21 joints, segments 2-6 being fused together, while in the 

 male the grasping antenna resembles that of an Acartia ; the 

 abdomen is long, and terminates in two long furcal rami which 

 are symmetrical. 



ACARTIELLA KEMPI, sp. nOV. 



(PI, XX., figs. 1-5, and PI. XXI., fig. 4.) 

 ?. Total length, 1-0 mm. 



Proportional lengths of cephalothorax and abdomen, 2'5 : 1, 



The head and first thoracic segment are separate, thoracic 

 segments 4 and 5 are fused together, the posterior thoracic 

 margin is rounded and devoid of spines. The anterior head 

 region is uniformly rounded, and the rostrum is absent. 



The abdomen consists of three separate segments having, 

 with the f ureal rami, the following proportions : — 32 : 15 : 25 : 

 34. The first segment is devoid of spines, thus difltering 

 from A. fortaniformis. 



The furcal rami are long and slender as in the genus Tortanus, 

 but are symmetrical. 



The first antenna, when folded back, reaches to the last 

 abdominal segment ; it consists of twenty -one separate joints, 

 having the following proportional lengths : — 



None of the segments possess spines. 



The second antenna resembles that present in the genus 

 Acartia ; it has a long endopodite and a short exopodite. In 

 this respect this species differs very considerably from 

 Acart'iella tortaniformis (Sewell), the only other member of 

 the genus in which this appendage is of a somewhat unusual 

 form. 



The mouth-'parts and swimming legs closely resemble those 

 of A. tortaniformis. 



