30. PTENUS. 51 



30. PTENUS. 



Ptenos, Nort. Trans. Amer. Ent. Soc. iv. p. 77 (1872). 



Ptilia, sect. 2, Nort. 1. c. ii. p. 367 (1869). 



Dielocera, Cameron, Trans. Ent. Soc. Lond. 1878, p. 145. 



1. Ptenus serratus. 

 (Plate IV. figs. 2 & 3.) 



Male. Exp. al. 8 (?) lin., long. corp. 5 lin. 

 Female. Exp. al. 1 poll., long. corp. 6 lin. 



Male. Head above, antennae, and thorax black, shining ; abdomen 

 with a slight violet shade ; cheeks shading into testaceous below. 

 First two joints of antennae testaceous, the first twice the length of 

 the second and pear-shaped, the second short, and with a strong 

 projection inwards, making it appear to be placed obliquely ; third 

 joint thick, furcate, and densely pilose. Pace, prothorax, pectus, 

 legs, and the middle of the abdomen beneath testaceous ; prothorax 

 densely clothed with short hair in front, giving it a serrated appear- 

 ance at the edges. Wings clear hyaline, with piceous nervures ; 

 stigma black ; fore wings with four submarginal cells on the right 

 side and five on the left. 



Female. Closely resembles that of Dielocerus ellisil. Head, thorax, 

 and legs testaceous ; first two joints of antennae, and sometimes the 

 base of the third, testaceous ; third joint black, ^smooth, longer and 

 more erected than in D. ellisii. Abdomen violet-black, except at 

 the base beneath ; hind tibiae black, and the four last joints of the 

 hind tarsi brown above. Eore wings hyaline, with four submar- 

 ginal cells, the second receiving both recurrent nervures ; a bulla 

 on the nervule dividing the first and second cell. The violet-brown 

 band is narrower and lighter, but more sharply defined than in 

 D. ellisii, and the base and apex are similarly dusky. Hind wings 

 as in D. ellisii. 



Two males and two females of this interesting species stood 

 among the series of D. ellisii in the British Museum. The extreme 

 apex of the wings is damaged in all our specimens of P. serratus. 



Hah. Brazil. 

 a-d. <$ 2 • (Types of species.) Catagallo. Presented by F. Smith, Esq. 



2. Ptenus sulcicornis. 



Dielocera sulcicornis, Cameron, Trans. Ent. Soc. Lond. 1878, p. 145. 

 Hob. Prainha. 



3. Ptenus americanus. 



Tenthredo americana, Linn. Syst. Nat. i. p. 555, n. 6 (1758) . 

 Hylotoma brasiliana, Klug, Berl. Mag. vi. p. 308, n. 40 (1814). 



Eab. Bahia. 



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