24 



DIPTERA. 



MESOGRAMMA. 

 Toxomerus, Macquart, Dipt. Exot. 5 C Suppl. p. 92 (1855). 



Mesogramma, Loew, Centur. n. P . 47 (1865) • Berl. ent. Zeitschr. 1865, p. 157. 

 Mesograpta, Loew, Centur. x. p. 290 (1872) ; Berl. ent. Zeitschr. 1872, p. 114. 



I have restored the name Mesogramma in place of Mesograpta, as the change was 

 arbitrarily made by Loew on the plea that Mesogramma had been used for a genus of 

 plants. As zoologists admit no conflict between zoological and botanical terms, the 

 change cannot be consistently accepted. 



The remarks under Sphcerophoria are yet more applicable here. I do not wish to 

 add to the confusion already unnecessarily increased by Bigot, and so refrain from 

 adding new names for others to puzzle over. 



Synopsis of the recognized Central-American species. 



1. Scutellum yellow *• 



Scutellum black, witli or without a yellow border 5. 



2. Abdomen with a yellow lateral margin marginatum, Say. 



Abdomen not margined with yellow 3. 



3. Second, third, and fourth abdominal segments with the anterior 



margin, a median stripe, and a pair of oblong, sometimes 



confiuent, spots, yellow. (8-9 millim.) politum, Say. 



Abdomen not so marked 4. 



4. Abdominal bands straight, uniform .' Sp. (no. 8). 



Abdominal bands irregular . . : ? mutuum, Say. 



5. Lateral margins of the mesonotum with a complete yellow 



stripe 6. 



Humeri, and sometimes the postalar callosities, only, yellow . 8. 



6. Larger species (8-9 millim.) ; fourth abdominal segment with 



a narrow anterior margin and median stripe, and a slender 



oblique spot, contiguous with the lateral margin, yellow . saphiridiceps, Bigot. 



Smaller species. (5-7 millim.) 7. 



7. Mesonotum deep shining black, with cinereous line and lateral 



stripe Sp. (no. 6). 



Mesonotum olivaceous or reddish, subopaque between the 



cinereous line and the lateral stripe pallipes, Bigot. 



8. Second abdominal segment shining black (<£) Sp. (no. 4). 



Second abdominal segment with an opaque black spot . . . Sp. (no. 5). 



1. Mesogramma saphiridiceps. 



Mesograpta (?) saphiridiceps, Bigot, Ann. Soc. Ent. Fr. 1884, p. 105 K 



Hab. Mexico \ Xucumanatlan 7000 feet, Omilteme 8000 feet (H. H. Smith). 



