REPORT ON THE COPEPODA. 57 



1. Scolecithrix dance, Lubbock (PI. XVII. figs. 1-12). 



Undina dance, Lubbock, On some Entomostraca collected by Capt. Sutherland, Trans. Entom. Soc, 

 vol. iv. 1856, p. 15, pi. ix. figs. 6-9. 



Cephalothorax robust (fig. 1), in the female usually not more than twice as long as 

 broad, in the male somewhat more slender. Anterior antennae (figs. 2, 3) about as long 

 as the cephalothorax, in the male nineteen-jointed, strongly arcuate, but not angulated, in 

 the female twenty-jointed; the first two joints in both sexes are stout and of moderate 

 length; they are followed by five very short and equal joints ; the seventh joint in the 

 female, the eighth in the male, is equal in length to the preceding five, and in some cases 

 is indistinctly divided into four; the remaining joints do not vary greatly in length, 

 except that the last (in the female) is very minute. Mandibles (fig. 5) rather narrow at 

 the apex, basal joint of the palp large, smaller branch two-jointed, larger indistinctly 

 divided into several joints. Inner branch of the maxilla (fig. 6, a) very small, composed 

 of one or two (?) minute setiferous digits. The anterior foot-jaw (fig. 7) has four stout 

 marginal processes, armed, as usual, with strong plumose setse, the terminal joints bearing 

 about six thick fusiform filaments, which are about half as long as the marginal setse, and 

 are filled with granular protoplasm. Posterior foot-jaws well developed and formed like 

 those of Calanus. Inner branches of the first pair of feet one-, of the second two-jointed, 

 of the third and fourth pairs three-jointed, the first joint in all cases very small. Ter- 

 minal spines of the swimming feet (fig. 8) strongly serrated on the outer and setose on 

 the inner margin. Fifth pair in the female wanting, in the male (fig. 9) elongated, 

 slender, that of the left side unbranched, the right bearing a simple one-jointed iennr 

 branch, which opposes the clawed extremity of the outer branch. Abdomen in both sexes 

 four-jointed, in the male slender, in the female (figs. 11, 12) short and stout, the first 

 seo-ment as large as the following three, tumid and prominent in front, where it is pro- 

 duced downwards, forming a pouch-like extension. Caudal segments distant, as broad as 

 long, length about equal to that of the second or third abdominal somite ; setse sub-equal 

 in length, not much exceeding that of the abdomen. Colour of the animal dark brown ; 

 length 1-1 lth of an inch (2 - 3 mm.). 



The drawing of the female anterior antenna (fig. 3) is not quite accurate ; no division 

 should have been shown in the large first joint (though an imperfect one sometimes 

 exists), and the last joint should have shown an extremely small segment at the apex. 

 The large basal portion of the male antenna is, however, correctly given as divided into two. 



Habitat. — Off Port Jackson, Australia; off Kandavu, Fiji ; between Api and Cape 

 York ; between Arrou and Banda ; at several stations amongst the Philippine Islands ; off 

 the east coast of Japan (Station 237) ; in lat. 32° 24' S., long. 13° 5' W. (Station 335) ; 

 in lat. 9° 43' S., long. 13° 51' W. (Station 342); in several Atlantic stations from lat. 

 3° 10' N., long. 14° 51' W. to lat. 26° 21' N., long. 33° 37' W. (Stations 348-353). 



(ZOOL. CHALL. EXP. — PART XXIII. — 1883.) Z 8 



