PARASITIC COPEPODS — WILSON 573 



and attached to the sides of the sinus close to its base (fig. 33). 

 The seminal receptacles are unique in that they are not circular 

 as in most species but irregularly ovate. Each is so large that it 

 nearly fills the entire anterior corner of the abdomen and is sur- 

 rounded with a fleecy packing that looks like cotton. This packing 

 is snow white and stretches back along the midline to the base 

 of the posterior sinus. These abdominal details are sufficient to 

 separate this from all other known species, 



Male. — The respiratory areas are shown in figure 31. The smaller 

 one has an elongate ovate form, the smaller end turned forward, 

 and fits into an invagination on the inner side of the larger one. The 

 latter is eidarged behind the invagination and narrowed in front of 

 it, with rounded ends. The abdomen is relatively much larger than 

 in the female and the testes, like the seminal receptacles in the female, 

 are exceptionally large and fill nearly all the abdomen in front of 

 the posterior sinus. The caudal rami are curved and lateral. In the 

 original description of this species in the reference given above it 

 was clearly distinguished from salminei. This distinction still holds 

 and with the addition of the details here given makes this species 

 undeniably valid. As stated there the two males found by Thiele 

 in the Copenhagen Museum and referred to sahninei do not agree with 

 Kr0yer's type male but do agree fully with this male paulensis and 

 evidently belong here. 



ARGULUS NATTERERI Heller 



Plate 24, Fiqukes 74-7S 



Argulvs mattereri Heixee, 1857, p. 103, pi. 2, figs. 4-12.— Kr0yer, 1863, pp. 97, 103, 



pi. 1, fig. 2a-d.— Thiele. 1904, p. 23, pi. 7, figs. 43-52. 

 Argulus salminei Meehean, 1940, p. 502 (part). 



Two females originally identified as belonging to this species were 

 declared by Meehean (1940, p. 503) to be "identical with A. paulensis,^' 

 but he placed in the vial containing them an autographed label that 

 read "identified as .4. salmiiui:' In furtherance of this last state- 

 ment the tigure of the respiratory areas in Meehean's species sahninei 

 w^as taken from one of these females. (See figure 74.) The color of 

 these preserved females is dark brown, the respiratory areas consider- 

 ably darker than the carapace. The color of the preserved paulensis 

 specimens is snow white and they are only half as large as the natterem 

 females. The first and second antennae correspond in every detail 

 with the figures given by Thiele for nattereri with not enough differ- 

 ence in the anterior protuberance of the first pair to be worthy of 

 mention (Meehean, 1940, p. 503). In one female all the teeth on 

 the basal plate of the maxilliped were short and broad but in the 

 other female (fig. 77) only the central tooth was short while the 



