112 REPORT OF XE\A' JERSEY STATE MUSEUM. 



Genus PANDARUS Leach. 



Pandarus Leach, Encyclop. Brit. Suppl. (Annulosa) 1816, p. 405. Type 



Pandarus bicolor Leach, first species. 

 Nogaus Leach, Diet. Sci. Nat., XIV, 1819, p. 535. Type Nogaus laireillii 



Leach, monotypic. 

 Nogagus, auct. 



Female. — Body an elongated oval or ellipse. Cephalothorax 

 semielliptical, usually narrowed anteriorly, and covered with a 

 smooth carapace without grooves. Posterior lobes short, margin 

 between them armed with teeth or spines, or sometimes sinuate. 

 Eyes usually invisible in adult, but visible in young. Free thorax 

 segments, each with pair of dorsal plates, these stiff, rigid, elytra- 

 form. Those on second segment lateral, others median, and third 

 pair overlapping to greater or less extent genital segment. 

 Latter considerably enlarged, elliptical, some narrowed pos- 

 teriorly and prolonged backward into lobes at posterior corners. 

 Dorsal surface of genital segment hardened like carapace, usually 

 gives evidence of being fusion of two plates like those of other 

 thorax segments. Sixth segment represented by a median lobe 

 or process attached to base of posterior sinus of genital segment, 

 without dorsal plates or rudimentary legs. Abdomen short and 

 broad, two-jointed, usually narrowed anteriorly and attached to 

 ventral surface of genital segment. Abdomen covered dorsally 

 by rudimentary sixth segment lobe, ventrally by short wide plate 

 and not reaching hind margin of dorsal lobe. Attached to either 

 side of ventral plate at base and to side of abdomen a peculiar 

 modified anal lamina. The two usually divergent, with thickened 

 conical outer margin and two membranous wings, dorsal and 

 ventral, on inner margin. Four pairs of adhesion pads on ventral 

 surface of carapace, one pair at base of first antennae, one at 

 base of second antennae, third between bases of first maxillipeds 

 and fourth on lateral margins of first pair of thorax plates, 

 opposite first legs. Second maxillipeds much swollen and en- 

 larged, armed with a pair of roughened forceps-like knobs in- 

 stead of terminal claw. Four pairs of biramose swimming-legs, 

 rami all laminate, indistinctly jointed, and usually armed with 



