405 



those of muhlenhergiae are slender and almost hair-like. The thoracic 

 respiratory organs in both species are stalk-like. The figure and de- 

 scription of our species give us no details of the legs and wings, but 

 smaragdinus is figured as having the wings extending to the apex of 

 second abdominal segment, the apices of fore tarsi to middle of 

 fourth, those of mid tarsi to apex of fifth, and those of hind tarsi al- 

 most to apex of abdomen. Both species have a single transverse 

 series of short spines on each dorsal abdominal segment, and peduncu- 

 late spiracles on lateral margins of segments i to 4. The apical seg- 

 ment in muhlenhergiae is armed with 4 thorns. 



It will be seen from the foregoing that the pupae offer as charac- 

 ters for distinguishing them from the pupae of Drapetis the peduncu- 

 late abdominal spiracles and the single transverse series of dorsal ab- 

 dominal spinules. The larvae I can not fully compare because I have 

 only a cast larval skin of Drapetis which affords no evidence as to 

 whether there are lateral abdominal spiracles in that stage. The loco- 

 motor spines differ somewhat, however, and if the figure of muhlen- 

 hergiae is dependable the head also differs in having a single saddle- 

 like dorsal plate. 



Both species of TJirypticus above mentioned live in stems of 

 plants ; neither species forms a cocoon like that of Drapetis. 



Medeterus lives in burrows of wood-boring larvae and also under 

 bark. Dr. E. P. Felt has recorded the larvae as feeding upon those 

 of Miastor. No species of this genus has been described in either the 

 larval or pupal stage from America. Perris has described the larva 

 and pupa of Medeterus amhigmis, a European species. The larva of 

 this species has the head very similar to that figured in the present 

 paper for Drapetis (PI. LVII, Fig. 6). The distinctions, judging 

 from Perris's figures, lie in the presence of only one series of locomo- 

 tor spinules on the abdominal segments, and in the tapering apical ab- 

 dominal segment, which ends in 4 short subcontiguous points, at the 

 apices of the upper and larger pair of which are located the posterior 

 spiracles. No mention is made of lateral abdominal spiracles, but 

 the prothoracic pair are figured. The pupa has the pair of cephalic 

 spines similar to those of Thrypticus, but slightly ventrad of them 

 are 2 much smaller protuberances. The thoracic respiratory organs 

 are long and slender. The fore tarsi do not extend beyond apices of 

 wings, the mid pair reach middle of fourth abdominal segment, and 

 the hind pair extend to middle of sixth. The dorsal abdominal seg- 

 ments possess 2 linear transverse series of spinules. 



A species of Systenus described by Laboulbene differs in the larval 

 stage from Medeterus in having the locomotor spinules situated upon 



