ESTEELY. — CALANOID COPEPODA FROM THE BERMUDA ISLANDS. 225 



point is the character of the spines on the posterior border of the last 

 thoracic segment; in bennudensis (Plate 2, Figure 17) these are much 

 smaller, shorter and more numerous than in spinata (Figure 16). In 

 the males of bermud^nsis the ventral group of spines on the border of 

 the last thoracic segment is replaced by hairs (Plate 2, Figure 18). The 

 distribution of spines and hairs on the abdominal segments is shown in 

 Figures 17 and 18 of Plate 2. 



This species lacks the rostral filaments. In the females the anterior 

 antennae reach back to the end of the genital segment, in the males to 

 the posterior border of the third thoracic segment. 



The genital segment in the females is almost as long as the rest of 

 the abdomen (Plate 2, Figures 10, 17), and the furca is about a third 

 longer than wide. In the male the genital segment (Plate 2, Figure 18) 

 is three-fifths as long as the second segment ; the second is a little 

 longer than the third and three times as long as the fourth. The 

 length of the cephalothorax along the mid-dorsal line is three times its 

 greatest width (Plate 1, Figure 1). 



The fifth feet show specific characters. In the female (Plate 4, 

 Figure 43) the middle joint of the fifth foot carries a blunt flap-like 

 process on the inner margin, which reminds one of an inner ramus. 

 The fifth feet of the male are shown in Plate 3, Figure 22. 



This Acartia was common in hauls around Agar's Island, while spin- 

 ata is quite rare in that locality ; the reverse is the case in collections 

 taken from the vicinity of North Rock. A. bermudensis belongs to the 

 clausi-discaudata group. 



The males average .9.3 mm. in length, the females .86 mm. The 

 animals are transparent and practically colorless. 



Occidental College, 

 Los Angeles, California. 



Bibliography. 

 Brady, G. S. 



'83. Report on the Copepoda collected by H. M. S. "Challenger'' 

 during the years 1873-76. Challenger Reports, vol. 8 (Part 

 xxiii), 142 pp., 55 pis. 



Breemen, P. J. van 



: 08. Copepoden. Nordisches Plankton, Siebente Lieferung, viii -f 

 264 pp., 251 Fig. 



Dahl, F. 



'94. Die Copepodenfauna des unteren Amazonas. Ber. Naturf. Gesell. 

 Freiburg, Bd. 8, pp. 10-23, Taf. 1. 



