30 T. V. HODGSON. 



The pleopocla are four paired structures occupying the entire area below the caudal 

 shield. Each pleopod consists of a very liroad and short basal joint bearing an 

 exopodite and an endopodite, which lie over one another, the exopodite being the. outer 

 or more ventral structure. The exopodite of the first gill is the largest and coarsest 

 in structure, forming an operculum over the rest. The plate is obliquely divided into 

 two by a suture, and its stout straight inner margin is thickly fringed with fine setae ; 

 the outer margin, which is rounded anteriorly and wide, tapers slowly to a blunt point 

 and is fringed with rather long plumose set*. The endopodite is much more delicate, 

 rather smaller, having no setae whatever, and it is not divided, though its outer margin 

 bears a conspicuous notch where the division should be. The posterior gill is shorter 

 and broader than the preceding one ; the exopodite is obliquely divided, but the only 

 setae it bears are a few of both kinds at the distal extremity ; the endopodite resembles 

 that of the first gill. 



The uropoda are attached to the caudal shield where the edge becomes dentate ; 

 the basal joint is short, expanded distally, and prolonged on the inner side into a 

 spinous process. The exopodite is two-jointed, the terminal one being scarcely half as 

 long as the other, pointed, and having two serrations on the outer side and two spines 

 on the other. The endopodite is a little longer than the first joint of the exopodite, 

 and its external margin is serrate and has a few setae in addition ; the internal margin 

 is also serrate but only distally. 



Two males and fragments of two others, sex uncertain, were taken by the 

 ' Discovery' in lat. 67 21' 46" S., long. 155 21' 10" E., 254 fathoms, bottom mud. 

 The trawl passed over a patch of stones probably dropped by some wandering iceberg, 

 and brought up so large a quantity of these that the specimens were very severely 

 damaged, and the trawl had to be slit up completely to save anything. 



Both Dr. Studer's and Mr. Beddard's descriptions of Serolis cornuta are defective 

 in many points. The niceties of specific discrimination as now understood were 

 altogether unknown in Eights' day. Almost invariably the defects of previously 

 published descriptions are those of omission rather than commission, and going through 

 them exhaustively with the ' Discovery ' specimens before me, I have no hesitation what- 

 ever in definitely stating that the ' Gazelle ' and ' Challenger ' specimens are immature 

 specimens of Scrolls trilobitoides Eights, and that the ' Discovery ' specimen is only 

 just arriving at the adult stage. 



CYMODOCELLA. 



Pfeffer (11), pp. 10!t-110 ; Hansen (7), p. 107. 



The following definition of this genus is by Dr. Hauseu 



Both sexes similar without processes. 



Distal part of the abdomen somewhat produced, with the lateral walls bent 



strongly downwards and inwards, constituting rather a long tube open 



at both ends and with a slit on the lower surface. 



