OP NEW ZEALAND. 1431 



Placodium. 



Nov. gen. 



Head nearly as large as the thorax, narrowed and somewhat 

 prolonged anteriorly, finely margined in front of the eyes. Antennal 

 tubercles absent. Eyes moderately large below, not at all pro- 

 minent above. Antennce inserted below the lateral margins of the 

 forehead, 11-articulate, joints 3-10 transverse. Tarsi with the 

 basal joint minute, second longest, with one claw. Abdomen com- 

 posed of six segments. Palpi (maxillary) with large subovate 

 terminal joints, third short, second elongate, its basal portion 

 slender, first small. 



Two characters distinguish this from Euplectus — the absence of 

 antennal tubercles, and the structure of the antennae. 



2484. P. zenarthrum, u.s. Subdepressed, elongate, moderately 

 nitid, rufo-castaneous, the three first dorsal segments infuscate, legs 

 and antennge fulvescent ; pubescence slender and decumbent. 



Head nearly flat, finely, closely, and somewhat rugosely sculp- 

 tured, not glossy, with two small simple foveae on the vertex. 

 Thorax widest near the middle, only slightly longer than broad, 

 about as much narrowed in front as it is behind ; its surface ap- 

 parently impunctate ; there are three foveae, united by a linear 

 impression, near the base, and an indistinct, rather short, dorsal 

 groove. Elytra oblong, their sutural striae broad and deep, 

 the intrahumeral impressions elongate. Hind-body, at the base, 

 as broad as the elytra, each segment slightly but distinctly nar- 

 rower than its predecessor, the basal three marginated. Legs 

 moderately stout. 



Antennce stout ; first joint short, hardly longer than broad; second 

 rotundate ; third much smaller, not half the size of the second, trans- 

 verse ; fourth very short and transverse ; fifth transverse, distinctly 

 larger than the contiguous ones ; 6-8 each very short, broader than 

 long ; ninth and tenth transverse, yet not as broad as the preceding 

 ones ; eleventh large, acuminate ; the point of articulation not being 

 exactly in the middle of some of the joints, the antennge appear 

 unsymmetrical. 



Male. Underside, first abdominal segment concealed by the 

 femora, flat between the coxae ; second nearly twice the length of 

 the third ; fourth strongly curved behind, so that its sides are twice 

 the length of the middle ; fifth extremely short ; sixth large, with 

 a large rounded apical cavity, this is bordered behind by a thin, 

 strongly-curved lamina. Front coxes prominent, exserted, and sub- 

 contiguous ; the trochanters with short cylindrical processes ; there 

 is a fovea in front of each of these coxae. Middle coxae subglobose, 

 not contiguous, the intervening mesosternal lamina moderately 

 thick. Hind coxae distinctly separated. 



Stermmi pale reddish-chestnut ; abdomen fuscous, except the pale 

 terminal segment ; metasternum large, flattened along the middle. 



Length, f ; breadth, nearly i line. 



