REPORT ON THE COPEPODA. 61 



the cephalothorax, twenty-four-jointed, many of the joints laterally produced and 

 angulated at the apices, the third, seventh, eighth, thirteenth, seventeenth, twentieth, 

 and twenty-second joints each bearing a very long apical seta, equal in length 

 to about one-third of the antenna; the twenty-third joint (penultimate) has two long 

 and two or three shorter setae, and in addition to the long setae the intermediate 

 joints have mostly one or more short ones. In the male the anterior antenna is 

 slightly angulated at the twelfth joint (PL XVIII. fig. 8), thickly fringed with short setae 

 near the base, more sparingly beyond, and has likewise a few scattered longer setae ; these, 

 however, are not nearly so long as in the female ; the eighth and ninth joints are 

 coalescent. The mandible in the female (PL XIX. fig. 4) is broad and strongly toothed at 

 the apex, palp large, with a broad base and two short biarticulate branches : in the male 

 (PL XVIII. fig. 9) there is no biting segment, and the palp is very small : the outer branch 

 of the maxilla is obsolete (PL XIX. fig. 5, and PL XVIII. fig. 10), and the whole limb is in 

 the male minute. The anterior foot-jaws are of moderate size in the female, but rudimentary 

 in the male. Posterior foot-jaws very large in the female (PL XIX. fig. 7), with two long- 

 basal and five small apical joints, very small in the male (PL XVIII. fig. 12). The outer 

 branches of all the swimming feet are three-jointed, except that of the first pair in the 

 female, which is only two-jointed (PL XIX. fig. 8). The inner branches of the third and 

 fourth pairs in both sexes are three-jointed. That of the first pair in the female has one 

 joint only, in the male one (or sometimes two) joints. In both sexes the inner branch of 

 the second pair has only one joint. The fifth pair of the male (PL XVIII. fig. 13) are of equal 

 length, that of the left side simple, ending in a very long subulate joint, the basal joint 

 bearing a rudimentary rod-shaped inner branch which is as long as the second joint ; the 

 terminal joint of the right foot has one long and slender apical spine and another much 

 smaller one ; it has also, springing from its inner margin, a stout appendage, which is 

 dilated and toothed at the apex and fringed on the margin with minute hairs ; in the axil 

 between this and the main portion of the limb is a small conical ciliated process. (The 

 immature fifth feet of Euchceta sutherlandii, Lubbock, are represented in fig. 14). The 

 abdomen is sometimes slightly pubescent, the last segment in both sexes always very 

 short, the second caudal seta of the female is extremely long, often longer than the whole 

 body of the animal, the others variable in length but not longer than the abdomen. The 

 two branches of the posterior antennas (PL XIX. fig. 3) are nearly equal in length ; the 

 inner branch four -jointed, first and third joints very short, bearing three apical and four 

 lateral setae. The second pair of feet in both sexes (PL XIX. fig. 9) differs from the rest 

 in having the spine-bearing angles elongated into small finger-like processes. The serra- 

 tures of the terminal spines of all the feet are extremely delicate, about fifty or more on 

 each spine. The external egg-masses are not enclosed in a definite sac, but are loosely 

 aggregated like bunches of grapes. 



Habitat. — Off Port Jackson, Australia ; between Sydney and Wellington ; off Kan- 



