PARASITIC COPEPODS — WILSON 563 



were taken open into it. Hence these two males and two females came 

 from exactly the same locality as the original type females. It is also 

 worthy of note that all the specimens of both sexes were caught swim- 

 ming freely in the tow. 



ARGULUS MEGALOPS SPINOSUS, new variety 

 Plate 26, Figxibes 95-104 



Dr. Frits Johansen obtained 32 specimens, including both sexes, 

 from the outside surface of an eel-backed flounder {Liopsetta putnanii) 

 at Cape Tormentine, New Brunswick, in the Gulf of St. Lawrence. 

 The male allotype and female holotype are U.S.N.M. No. 60460. Forty 

 specimens, also including both sexes, were taken from the skin of the 

 long-spinecl sculpin {Acanthocottus ocfodecimspinosus) in the Gulf 

 of St. Lawrence. 



Female. — Carapace elliptical, the length to the breadth as 5 to 4 and 

 to the length of the entire body as 5 to 8. Posterior sinus broadly 

 triangular and shallow, posterior lobes reaching the center of the 

 third segment. Abdomen broadly elliptical, the width to the length 

 as 11 to 13; anal sinus narrow and short, caudal rami basal. Fourth 

 thoracic segment as wide as the third, with broadly rounded lobes at 

 its posterior corners. 



Second segment of the first antenna with a stout curved spine on 

 its anterior margin, a straight spine on the ventral surface near the 

 posterior margin and a large and strongly curved lateral claw. The 

 middle segment of the terminal portion of the antenna has two large 

 spines at its distal end and the terminal segment is tipped with three 

 spines. The basal segment of the second antenna has a very stout 

 and blunt spine on its ventral surface close to the proximal end. The 

 second, third, and fourth segments diminish rapidly in length, the 

 fourth a third as long as the second. All four segments are girdled 

 with long and slender spines, numbering respectively eleven, six, four, 

 and three. The supporting rods in the margins of the sucking disks 

 are each made up of six segments nested one within another, the basal 

 one twice as long as the others. The maxilliped is stout and fairly 

 spiny on its ventral surface. The swimming legs are practically 

 identical with those of the regular female of the species and are with- 

 out flagella. 



Male. — Carapace ovate, longer than wide, with a deep sinus on 

 each lateral margin opposite the compound eyes forming a prominent 

 shoulder.^ Posterior sinus enlarged at its base, posterior lobes reach- 



9 The male of Argulus dactylopteri ThoreU (1865, p. 609, pi. 16) shows an even more 

 prominent shoulder. 



