Kramer. — Pelagic Gopepods and Cladoceres of Auckland. 223 



the open gulf, there was a large number in all states of de- 

 velopment. At times the number was so large that of ten 

 organisms in the draught one was a Penilia. No males were 

 found ; they seem to live at another time. The females had 

 nearly all some eggs or embryos (I saw once eight) in the 

 brood-bag. 



In the middle of the head, one eye surrounded with 

 crystal lenses (fig. 3, d) ; one rostral spine on each side of the 

 head (figs. 1, 2, 3). Behind the rostrum the first antenna, a 

 small one-jointed palpus with some short setae on the end 

 (fig. 2) (one larger and some smaller) . The second antenna (fig. 4) 

 is long (the rowing-antenna) and two-branched ; each branch 

 is two-jointed. The ramus externus (B.e.) bears six setae 

 on the last (2) and two on the first segment. The ramus 

 internus (B.i.), four and one. Each segment is armed with a 

 small spine. Behind the eye is the heart (fig. 3, c), and 

 between the eye and heart a secondary eye (b) . On each side 

 of the heart is a sucking-disc (a). 



The integument of the body, the shell, covers six leaf- 

 shaped feet (branchipods) , and is slightly denticulated on 

 the margin. The form of the shell in reference to the head 

 and the abdomen is best seen in fig. 1, and described below in 

 comparison with the species of Dana. 



The length of the animal is about 1mm. (^ni.). 



The abdomen (fig. 5) is armed with two long stylets, each 

 bearing two small thorns (a longer and a shorter one). The 

 stylets are about as long as the abdomen. Two long setse 

 (about as long as the body) are placed on tw ? o appendages of 

 the upper part of the abdomen. 



The difference between the three species is, — 



P. AVIROSTRIS. 



Posteriorly over the 

 middle of the back exca- 

 vated; anteriorly form- 

 ing an acute angle with 

 the head. 



P. ORIENTALIS. 



Shell. 



Posteriorly shallow exca- 

 vated; anteriorly form- 

 ing no acute angle with 

 the head. 



P. PACIFICA. 



Posteriorly a little exca- 

 vated; anteriorly form- 

 ing an acute angle with 

 the head. 



Not so long as the caudal 

 stylets, barely reaching 

 to the base. 



Seto3 of the Dorsal Appendages of the Abdomen. 



Very long, reaching far 

 beyond the apex of the 

 stylets (as long as the 

 body). 



Long, reaching beyond 

 the apex of the stylets. 



Palpus (Ant. I.). 

 Present. I No palpus. | Present. 



As I mentioned above, I also found P, pacifica in Port 

 Jackson, and another new and distinct species in the crater- 

 lake Lanuto'o, in Samoa, 2,000ft. above the level of the sea. 



