354 BULLETIN OF THE BUREAU OF FISHERIES. 



outline, very minute and thickly scattered, especially near the margin of the carapace. On the carapace 

 there are also blotches of pale reddish brovm, much larger than the white spots and more widely scattered. 

 Each blotch has a small spot near the center where there is no pigment; immediately around this spot 

 the pigment is deeper in color and pales gradually toward the edges. The dorsal surface of the thorax 

 over the eggs is a rich golden yellow, thickly streaked with longitudinal rows of purplish brown blotches, 

 smaller than those on the carapace, deeper in color, more uniform in size, and more regular in shape. 

 Most of these blotches also have small circular spots free from pigment, sometimes two to fouir in the 

 same blotch and of different sizes. The eyes are deep golden yellow, each separate facet with a dark 

 purple center. The sperm receptacles are golden yellow. 



Although the species was originally foimd outside of the Mississippi Valley, there seems to be no 

 doubt that it belongs here. Its wide distribution and the variety of hosts show that its range is universal 

 throughout the eastern and central United States. 



Argulus ingens Wilson. 



Argulus ingens Wilson, Proc. U. S. Nat. Mus., vol. 4a, p. 233, pi. 30. 



Host and record of specimens. — Both sexes of this species were obtained from the alligator gar, Lepiso- 

 steus tristoechus, at Moon Lake, Miss. 



No alligator gars were captured during the present summer, but they are fairly common in the 

 Mississippi River, and when carefully examined will probably yield specimens of this parasite. 



Argulus nobilis Thiele. 



Argidus nobilis Thiele, 1904. Mitteil. aus dem Zool. Mus. Berlin, II Band, 4 heft, p. 28, pi. 7, 8, fig. 64-76. 



Host and record of specimens. — Thiele found six females and one male of this species among the 

 specimens of the Berlin Zoological Museiun; the name of the host upon the museum label was given as 

 " Lepidosteus acuUatus." No such association of names is known in ichthyological literature, noris 

 there any hint as to whether the mistake was made in the generic or the specific name, so that we are left 

 in a quandary as to its identification. Thiele suggested that it may have been "L.ximdii," which is the 

 name given by Giinther to the alligator gar, but this was only a guess and was unaccompanied by any 

 proof. 



Remarks. — The present species differs from ingens in the relative size of the abdomen and carapace, 

 in most of the details of the first and second antennae, in the general structure and armatm-e of the 

 raaxillipeds, and especially in the accessory sexual apparatus of the second and third swimming legs 

 of the male. The two species resemble each other in their exceptionally large size, in the general form 

 of the abdomen, and in the approximation of the two outer spines on the basal plate of the maxillipeds. 

 Nothing is stated with reference to the respiratory areas of nobilis, but those of ingens are very peculiar, 



If Thiele 's conjecture that the alligator gar is the host of this species should prove true, it would 

 greatly increase the probability that ingens and nobilis are synonymous, and Thiele 's name would take 

 precedence. 



At present, however, there are so many specific differences, and the identity of the host is so uncer- 

 tain, that we can only leave the species as described and await future developments. 



Argulus maculosus Wilson. 



Argulus maadasus, Wilson, Proc. U. S. Nat. Mus., vol. 25. p. 715, pi. 19. 



Host and record of specimens. — The original types of this species were 11 females and 3 males, found 

 unlabeled in the National Museum collection, and a single female from the muscalonge, Esox nobilior, 

 at Clayton, N. Y. Since then two females were obtained from the red-eye, Ambloplites rupestris, at 

 Lake Maxinkuckee, Ind., August 8, 1906, and a single female from the yellow catfish, Ameiurus natalis, 

 August 22, from the same locality. Numerous specimens were subsequently obtained from the two 

 catfish, Ameiurus nebulosus and A. natalis, at Lake Maxinkuckee, and these are evidently their true 

 hosts. (Proceedings U. S. National Museum, vol. 32, p. 416). 



Some egg strings were obtained from these last ripe females and have received catalogue no. 32826, 

 U. S. National Museum; the newly hatched larvae (catalogue no. 32822, U. S. National Museum) were 

 fully described in the last reference above given. 



Remarks.— There is nothing to add to the full descriptions already given. Only one mutilated 

 specimen has yet been found from the Mississippi River, but as the two catfish are plentifully distributed 

 throughout the valley no doubt more will be discovered in the future. 



