26 EXPLANATION OF TERMS 



Penultimate, the last but one. 



Perennial, continuing for several years. 



Perfoliate, perforated ; applied to those antennae of which the 

 joints are transversely divided into thin plates, which are con- 

 nected by a common stalk passing nearly through their cen- 

 tres. See clavate, pectinate. 



Peristaethium, that segment of the postpectus anterjor to the 

 insertion of the intermediate feet; it extends laterally to the 

 scapulas, and is generally connected with the pectus by a 

 membrane. 



Persistent, permanent, 



Personate, gaping. 



Petiolated, supported on a stem ; (cellule) one of the cubital 

 cellules is said to be petiolated when it is triangular, and con- 

 nected by means of a nervure with the nervure of the radial 

 cellule; this disposition more frequently occurs in the second 

 cellule. 



Petiole, a stem ; the support which connects the base of the 

 metathorax with the base of the abdomen. 



Phallus, the masculine organ of generation. 



Phosphorescent, lucid ; emitting light in the dark. 



Piceous, pitchy ; the colour of pitch. 



Pilous, having long sparse hairs. See hirsute. 



Pinnatifid, with winged clefts. 



Plane, a level or rectilinear surface, destitute of elevations or 

 depressions ; a curved surface cannot be plane because it is not 

 rectilinear. See equal. 



Planta, the basal joint of the tarsus of the posterior pairs of feet 

 in Hymenoptera, often dilated or elongated, containing scapula. 

 See palma. 



Pleura, the side of the stethidium, between the thorax and 

 pectus. 



Plicate, plaited ; folded like a fan. 



Plumous, feathered ; with fine hairs on each side so as to re- 

 semble a feather. See pennaceous. 



Poisers, the halteres, in the Diptera, a capitate moveable fila- 

 ment on each side, substituted for the inferior wings. 



Polliniferous , formed for collecting the pollen of plants, as in 

 many of the Hymenoptera. 



Polymorphous, undergoing a metamorphose ; applied to those 

 articulated animals with feet that undergo a metamorphose, 

 either partial or total. See homotene. 



Polyphagous, eating a variety of food. 



Porcate, marked with raised longitudinal lines. 



