342 



DISCOVERY REPORTS 



the secondary blade in the form of a single toothed spine. The cutting edge of the left 

 mandible is narrower than that of the right and is undivided ; its inner secondary blade 

 is in the form of two spines, the larger one of which has a bifid extremity. 



The outer lobe of the maxillula bears ten stout spines, and a single more slender 

 pectinate one, on its truncate distal extremity. The maxilla (Fig. i d) differs from that of 

 all the other species of Serolis except S. orbicidata, n.sp., in possessing only one articu- 

 lating lobe instead of two. This lobe bears four pectinate setae at its distal extremity, 

 and fourteen similar setae are present on the distal end of the fixed lobe. There appears 

 to be no suture between the third joint of the primary axis and the lamella of the second 

 joint (for discussion on the morphology see p. 272). 



b. 



Fig. 17. Serolis nototropis, n.sp. 



a, two joints of the antennal flagellum, to show the conical scales, b. maxilliped of ^: x 50. c, second 

 thoracic appendage of (J: x 64. d, third thoracic appendage of (J: x 90. e, fourth thoracic appendage of 

 (J: X 67. /, uropod: x 83. 



The type of maxilliped met with in this species (Fig. 17 6) is intermediate between 

 that of S. exigua, Nordenstam, and that of S. schythei, LiJtken. The endopod springs from 

 the middle of a plate-like structure consisting of the basipodite [B) plus its endite {B') 

 and its lamella (£") : distally the endite and the lamella are separate for a short distance, 

 but the division does not extend as far as the articulation of the endopod. The endopod 

 is comparatively slender, and its distal joint is small and fringed on its inner margin 

 with long setae ; similar setae are also found on the distal half of the inner margin of the 

 second joint. 



