336 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



Cephalothorax-abdomen length ratio of female longimana Clans, 

 according to Giesbrecht (1892, p. 428), approximates 2.9 ±.3:1. 

 However, ratios of longimanna collected by GiM and Alaska similar 

 to range in paenelongimana; a female longimana from Gulf of Mexico 

 (unpublished data; lat. 23°50' N., long. 82°19' W., Jan. 19, 1952, 

 1 meter depth) with ratio of 3.8:1; two longimana females from off 

 Cape Lookout (unpublished data; lat. 34°03' N., long. 75°15' W., 

 Mar. 6, 1953, 35 meters depth) with ratios of 3.6:1 and 4.1 :1. Cephal- 

 othorax-abdomen length ratio, therefore, appears to be of no value 

 in distinguishing between individual females of the two species. 



Genital segment tends to be longer and furcal rami shorter in 

 female paenelongimana as compared to available specimens and 

 Giesbrecht's figures (1892, pi. 39, figs. 4, 6) of longimana. 



Remarks: The female can be easily recognized by the characteristic 

 ventral process of the second abdominal segment. While processes 

 from the vental surface of this segment are developed to varying 

 degrees in several species of Candacia, the process is directed anteriad 

 only in paenelongimana. Both Candacia chirura Cleve (fig. 2,n) and 

 O. armata (Boeck) have conspicuous processes, directed posteriad. 



The male can easily be confused with the male of longimana, but 

 can be distinguished by the shape of the process on the right side of 

 the fifth thoracic segment, especially when examined from the side. 

 In longimana this process is somewhat variable, but is relatively 

 shorter and heavier than in the single male paenelongimana. In 

 dorsal view (fig. 2,h-^) it is more pointed and usually curves medially. 

 Seen laterally (fig. 2,^) it bends abruptly upwai-d just beyond the 

 thickened middle and narrows uniformly to the pointed distal end. A 

 number of male specimens of longimana from both the Atlantic and 

 Pacific Oceans have been examined; in none of them did this process 

 closely resemble that of paenelongimana with its uniform curvature 

 and expanded apex. 



Literature cited 



Brady, Geoege Stewardson 



1884. Report on the Copepoda collected by H. M. H. Challewjer during the 

 years 1873-76. Rep. Sci. Res. Voyage of H. M. S. Challenger, Zool., 

 vol. 8, pt. 23, 142 pp., 55 pis. 

 Farran, George P. 



1929. Crustacea, pt. 10, Copepoda. British Antarctic (Term Nova) Expedi- 

 tion, 1910, Nat. Hist. Rep., Zool., vol. 8, No. 3, pp. 203-306, 37 figs., 

 4 pis. 

 Giesbrecht, Wilhelm 



1892. Systematik und Faunistik der pelagischen Copepoden des Golfes von 

 Neapel und der angrenzenden Meeresabschnitte. Fauna und 

 Flora des Golfes von Neapel, Monogr. 19, 831 pp., 54 pis. 



