DESCRIPTIOXS OF ARGULID^E— WILSON. 



655 



DORSAL SURFACE OF THE FREE THORAX OF 

 ARGULUS TRILISEATA. 



Color a uniform pale 3'ellow, deeper along the central axis and 



lighter toward the niaroins. The dorsal surface of the thorax is 



ornamented with three well-detined rows of dark ])rown y)igment spots 



which stand out prominenth' against the yellow background and catch 



the eye at once when the creature is 



viewed under a low power. The 



middle row is made up of a dozen 



large spots in single line along the 



central axis; the lateral rows are 



made up of numerous smaller spots 



arranged altei'natel}' in two broken 



lines. Under strong magnitication 



these spots are seen to be transversely 



ol)long and very irregular, the edges 



being cut repeatedl}' more than half 



the distance to the center (fig. 38). 



The large semen receptacles are also fig. 38.— one of the pigment sdots on the 



dark brown and show through the 



abdomen very prominently- 

 Locating this species in the artificial key already published « we 



should have: 



A. Carapace lobes overlapping the base of the abdomen. 

 B. Anterior swimming legs with a flagelluin. 



C. Carapace elliptical, considerably longer than wide. 

 7, a. Sucking disks only 0.12, far forward and widely separated; abdomen small, 

 spindle shaped, cut to the center. Color light yellow, with three rows 

 of dark pigment spots on the dorsal surface of the thorax trilineatn. 



{ti'es — three, lineatus — arranged in lines.) 



The author also desires to record the occurrence of Arguhis alosse at 

 Casco Bay on the coast of Maine. 



Several fine males were obtained from the common cunner {Otenola- 

 hrus adsjMrsus Walbaum), and they seemed fairlj' numerous. This is 

 the first instance where this species has been positively identified north 

 of Woods Hole since its original discover}^ b}^ Dr. Gould. And it 

 will increase the probabilit}' that the habitat may extend to the (Tulf 

 of St. Lawrence as doubtfully recorded by Mr. J. F. Whiteaves. 

 Incidentally also it is the first species of this family to be obtained 

 from the cunner, but as no females were found it may be inferred 

 that this was only a temporary host used during the breeding season. 



«Proc. IT. S. Nat. Mus., XXV, 1902, p. 701. 

 Proc. N. M. vol. xxvii— 03 46 



