138 ME. T. SCOTT ON ENTOMOSTEACA 



Cythere radula, Brady. 



Cijthere radula, Brady, Report on the ' Challenger ' Copepoda, p. 102, pi. xix. fig. 4 a, b. 



Habitat. Lagoon, Silo Thome Island, in tlie same gathering with the last. A single 

 valve evidently belonging to Cythere radula was obtained, but was broken while being 

 examined. 



Cythere rimosa, n. sp. (PL XIV. figs. i6, 47.) 



Shell tumid; seen from the side the dorsal margin is highest behind the middle, thence 

 it slopes gently in a nearly straight line to the anterior end, but merges behind into the 

 boldly and somewhat obliquely rounded posterior margin ; front margin subtrancate, 

 the lower part of the shell slightly produced ; greatest height equal to fully half the 

 length. The outline seen from above subovate, sides nearly parallel, but somewhat 

 wider in front of the middle ; thence they converge in a gently rounded curve to the 

 posterior end, which is slightly emarginate; greatest width scarcely equal to half the 

 length. Posterior extremity subtriaugular, with the apex truncate. Surface of the 

 valve curiously sculptured, with flattened ridges arranged in irregular and more or less 

 oblique lines extending across the shell. Length -6 mm. 



Habitat. Lagoon, Sao Thome Island, in a surface tow-net gathering, collected January 

 27th, also the same gathering with Gypria atlantica collected off the mouth of the river 

 Congo, at about 40 miles from land, February 18th. 



Cythere thalassica, n. sp. (PI. XIV. tigs. 48, 49.) 



Outline of shell, seen from the side, narrow, elliptical, highest at the middle ; greatest 

 height scarcely equal to half the length ; dorsal margin gently and evenly arched, ventral 

 margin nearly straight ; both extremities similarly and boldly rou.nded. Seen from above, 

 ovate, rather widest at the middle, width and height about equal; anteriorly the sides, which 

 are slightly rounded, converge gently towards the obtusely jiointed extremity ; posterior 

 end l)roadly and moderately convex. Surfaces of valves smooth. Length -85 mm. 



Habitat. In a lagoon, Sao Thome Island, in a surface tow-net gathering, collected 

 January 27th. One or two specimens only obtained. 



Cythere venijsta, n. sp. (PI. XIV. figs. 50, 51.) 



Shell, seen from the side, broadly eUiptieal ; greatest height behind the middle, scarcely 

 equal to half the length. The dorsal margin is slightly arcuate, middle portion forming 

 a nearly straight line, but gently curved in front to where it joins the boldly and evenly 

 rounded anterior extremity ; posterior margin moderately and regularly convex ; ventral 

 margin slightly concave. Seen from above the shell is broadly ovate, widest behind the 

 middle ; greatest width equal to five twelfths of the length ; sides evenly rovinded, con- 

 verging gently towards the anterior extremity, but more convex posteriorly ; extremities 

 bluntly angular ; valves somewhat unequal, the right being rather smaller than the left. 

 Surface of the valves ornamented with flattened and gently curved longitudinal ribs placed 



