434 D. J. SCOURFIELD ON A NEW COPEPOD FOUND IN 



Moraria arboricola sp. nov. 



Female. Body (fig. 1) long and vermiform, divided into nine 

 free segments, the first being the longest and the sixth (first- 

 abdominal) the second in length. Rostrum broad. Eye red or 

 brownish red, moderately large as a rule, but rather variable in 

 size and in outline. Dorsal plate on carapace rather variable 

 in shape, usually more or less rectangular with rounded angles r 

 slightly broader in front than behind. Posterior margins of all- 

 segments smooth on dorsal surface. On ventral surface abdominal 

 segments (fig. 16) armed as follows: 1st, with two widely 

 separated groups of about five teeth ; 2nd, with a row of teeth 

 from one-third to half width of segment, sometimes with central 

 teeth missing, thus leaving two isolated groups; 3rd, with a row 

 extending almost across segment ; 4th (last), with a row com- 

 pletely across segment and a little way round sides, except for 

 the slight interruption caused by the posterior median notch. 

 Anal plate or operculum (see fig. 15) more or less semicircular^, 

 with smooth but slightly wavy edge, and with faint dark and 

 light bands radiating towards the edge, showing probably that 

 the plate is very slightly corrugated. 



In the stage before the adult the edge of the anal plate is not 

 smooth, but furnished with a few very minute teeth, widely but 

 somewhat irregularly spaced (fig. 13). In the still earlier stages 

 the teeth are rather larger (fig. 12). The presence of teeth on 

 the anal plate in the young stages of M. brevipes, which also 

 has smooth edges in the adult, has been noted by Mrazek (4). 



Branches of furca (figs. 14 and 15) moderately long and taper- 

 ing considerably, with a prominent chitinous ridge on the dorsal 

 surface, ending posteriorly in a blunt tooth from the base of 

 which springs a spine directed upwards. Outer edges armed 

 with two strong spines, the proximal with a minute accessory 

 spine at its base. Inner edges with two curved rows of minute 

 teeth, terminating dorsally in little teeth on the chitinous plate. 

 Posterior edges with a row of teeth on the ventral surface, 

 covering bases of terminal setae. Terminal setae usually quite 

 smooth, three on each furcal lobe, inner very small, outer not 

 quite half the length of the median, which again is about half 

 the body length. The outer and median setae, especially the 

 latter, somewhat bulbous at the base. 



