KEVIEW OF GENUS ARGULUS MEEHEAN 495 



somewhat longer. Between the second and third swimming legs is 

 a slight spinous lobe on the lateral edges of the thorax directed from 

 the base of the third thoracic appendage anteriorly (fig. 32, c). On 

 the third and fourth appendages the basal segments are only about 

 half as long as those of the two anterior pairs. The basal segment 

 of the third pair is very broad, and a posterior lobe containing the 

 socket extends about two-thirds the length of the segment. The 

 peg is composed of a chitinous shovel-shaped lobe projecting laterally 

 from the distal end of the basis, with a fleshy protuberance directed 

 toward the appendage on the ventral side. Around the base of the 

 peg is the usual ridge ; the basis is enlarged posteriorly and a fleshy 

 posterior lobe is located on the coxa. There is a large papilla at 

 the ejaculatory duct on the end of the thorax. 



The host in this country is the goldfish {Carassius auratus), and 

 the species has been reported from almost every region where goldfish 

 are found. 



ARGULUS LATICAUDA Smith 

 FlGtTRE 33 



Argulus laticauda Smith, 1873, p. 574. — Wilson, 1902, p. 705, pi. 10. 



Carapace longer than wide, alae reaching fourth appendages of 

 male and abdomen on female; cephalic area broad and prominent, 

 with deep sinuses, posterior sinus broad. Abdomen orbicular, about 

 as wide as long; sinus about one-fourth the length of carapace and 

 broad; anal furcae basal. The respiratory areas consist of an 

 anterior smaller one opposite the maxillae and a posterior E-shaped 

 larger one (fig. 33, a). Females have been reported to 7 mm. and 

 males to 6 mm. 



Lateral hook of first antennae short but turned back on itself; 

 anterior knob long with slight indication of a hook at the end; 

 ventral spine on base of hook stout, spine at base of antenna broad 

 with a blunt end; flagellum just reaching beyond lateral hook. 

 Second antennae long, almost reaching the edge of the carapace; 

 spine at base very broad, postantennal spine very broad and long. 



Suction cups small, rims supported by ribs made up of three or 

 four straight rods (fig. 33, 5). Marginal lappets very large. Second 

 maxillae with narrow basal plate flaring widely into three truncated 

 lobes, which may be squarely cut but usually appear to be worn in 

 the center to give a slightly bilobed appearance. Postmaxillary 

 spines short, broad, truncated, and fairly inconspicuous. 



Swimming appendages with flagella. Female with small boot- 

 shaped natatory flap on posterior surface of coxa on fourth a^Dpend- 

 ages. Male accessory apparatus extremely complicated. Precoxa of 



