1919] Claassen: Chlaenius Impunctifrons' 99 



THIRD INSTAR LARVA. 



(Plate VI. Fig. 4). 



Antennce. First, second and third joints of- equal lengths. Fourth 

 joint about two-thirds the length of the other segments. 



Prothorax less than twice as wide as long, i. e., the width equals 

 one and three-quarters the length. 



Caudal processes as in the second instar. 



Measurements of Cast Skin. Length from tip of mandibles to tip 

 of caudal processes, 14.57 mm.; greatest width across throax, 3.43 mm. 



PUPA. 



(Plate VI, Fig. 2). 



The pupa is of a creamy white color. The eyes are the first to show 

 a mottled brown color. The mandibles also become chitinized early. 



Ventral view. Head bent under so as to show a small portion of the 

 prothorax. Labrum and clypeus together a third longer than broad, 

 emarginate in front. Mandibles long with a notch and tooth at the 

 apex. Maxillary and labial palpi plainly visible. Front of head with 

 four setee arranged as shown in figure. Antennse eleven jointed, the 

 tips almost reaching the tips of the metathoracic wings. Pro thoracic 

 legs extending to a point half way between the tips of the maxillary 

 palpi and the tips of the antennae. Mesothoracic legs underneath the 

 antennse, extending slightly beyond the tips of the antennae. Meta- 

 thoracic legs visible only at the tips where they project from beneath 

 the metathoracic wings. Elytra show the longitudinal striae plainly. 

 The elytra extend about two-thirds the length of the metathoracic 

 wings. Wings with a hump on the lateral margin. They extend back 

 to a point one-third across the fourth abdominal segment. Abdomen 

 with segments two to nine visible. Segment two with a small hair- 

 tipped tubercle on each lateral margin. Segments three, four and five 

 each with lateral processes as shown in the figure. Segments seven and 

 eight smooth. vSegment nine with two short posterior tubercles. 



Dorsal view. Dorsally the pupa presents a hairy appearance. 

 Long hairs occur on all but the last three abdominal segments. On the 

 thorax the hairs are shorter and occur more scatteringly. On segments 

 one to six, of the abdomen, the hairs are long and are arranged in two 

 groups on each segment; one group on each side of the median line. 

 The hairs are arranged in two more or less distinct row^s, thirteen hairs 

 in each lateral group, or twenty-six long hairs on each segment. 



Measurements of the living pupa. Length, 10.28 mm.; greatest 

 width of abdomen not including the lateral processes, 4.57 mm. 



ADULT. 

 (Plate VI, Fig. 6). 



The adult which emerged from the pupa in the laboratory measured 

 13.7 mm. in length and 4.7 mm. in its greatest width. The original 

 description of the adult is found in the Transactions of the American 

 Philosophic Society II, 64, 1823. 



