1911] Esterly: Copepoda of tht San Diego Region. 331 



position on the joint reaches nearly to the distal margin of the 



third joint. 



Length: 9.4 mm. 



Coloration: Whitish ami translucent in formalin, but unpigmented. 



Occurrence: Station 1075, vertical from 600 f., Dec. 17, 1905. 



Disseta sp. (Wolfenden). 



PI. 28, figs. 40, 41 ; pi. 30, tigs. 76, 80; pi. 31, fig. 100; pi. 32, figs. 107, 108. 



Heterorhabdus grandis, Wolfenden (1904), p. 120. pi. 9, fig. 36. 

 tDisseta i>itl<i>nht>i Giesbrecht, (Parran, 1908, p. 67). 



The figures given by van Breemen I 1898, p. 228, fig. 243) of 

 the fifth feet of the male of Heterorhabdus grandis Wolfenden 

 agree closely with those of a species of Disseta found in this 

 region. Farran (1908, p. 67). states that //. grandis Wolfenden 

 is identical with D. palumboi Gieshrecht. However, so far as I 

 am aware, the male of Disseta was unknown until I described 

 the male of D. grandis (Esterly, 1906, p. 71), and I can see no 

 reason for identifying II < h rorhabdus grandis with Dissi In 

 palumboi in view of the few figures of the former that have been 

 published. The length of D. palumboi is given as 5.7 mm., that 

 of H. grandis as 6.6 mm., while the length of the specimens under 

 discussion is 7.3 mm. In D. grandis Esterly the males are smaller 

 than the females. The following is a description of the male from 

 the San Diego region. 



Adult male. The head, as seen in side view, ends in a rather 

 abrupt angle, as do the edges of the last thoracic segment (pi. 28, 

 fig. 40). The rostral filaments are stiff and placed so far 

 beneath the head that they are invisible except from directly 

 below; the sides of the eephalothorax in front seem to be pro- 

 longed so as to cover the rostrum (pi. 28, fig. 41). 



The eephalothorax and abdomen are each 5-segmented and 

 the former is twice the length of the abdomen and furca. The 

 head is not fused with the thorax but the last two thoracic seg- 

 ments are fused with each other. The middle segment of the 

 abdomen is the longest one; the first and second are of equal 

 lengths and about four-fifths as long as the third; the fourth 

 is three-fourths the length of the third, and the fifth is about 



