DIPTERA. 237 



Hab. Mexico, Tampico (Saussure 7 ), San Bias in Jalisco (Schumann), Dos Arroyos 

 and Tierra Colorada in Guerrero, Teapa in Tabasco (H. H. Smith), N. Yucatan (Gaumer), 

 Merida in Yucatan 7 . — South America 1 2 , Brazil 5 6 9 10 , Chapada, Pernambuco 10 , Buenos 

 Aires n . 



Ten specimens. Placed by Osten Sacken amongst the unidentified Stratiomyidse 

 (antea, p. 42). 



3. Ptecticus cyanifrons. 



Sargus testaceus, Macq. Dipt. Exot. i. 1, p. 203 \ 

 Sargus cyanifrons, Rondani, Esame di varie Sp. etc. p. 43 2 . 



Ptecticus testaceus, var. cyanifrons, Giglio-Tos, Mem. della Reale Accad. delle Sci. di Torino, (2) 

 xliii. p. 118 3 . 

 Hab. Mexico, Tampico (Saussure 3 ), San Bias in Jalisco (Schumann), Orizaba 

 (Sumichrast 3 ), Teapa in Tabasco, Cuernavaca in Morelos (H. II. Smith), Merida in 

 . Yucatan 3 . — Brazil 1 2 . 



Three males and two females. The only perceptible difference between this and the 

 foregoing species is in the colour of the front, blue-black in P. cyanifrons and yellow 

 in P. testaceus. The colour of the tarsi, mentioned by Giglio-Tos, is variable. 



4. Ptecticus sackeni. 



Ptecticus sackenii, Willist. Canad. Ent. xvii. p. 124 1 . 



Hab. North America, New York, Virginia, Florida 1 (Coll. Univ. of Kansas). — 

 Mexico, Tierra Colorada in Guerrero (H. H. Smith). 



Four males and one female from Guerrero seem to agree with the specimens of this 

 species in the collection of the University of Kansas. They are rather smaller than 

 the types, and the stripes of the mesonotum are not so well marked. P. sackeni 

 apparently differs from P. cyanifrons only in the white colour of the hind tarsal joints, 

 and I am not sure whether it can really be considered as more than a variety. 



5. Ptecticus nitidipennis. 



Ptecticus nitidipennis, Loew, Verh. zool.-bot. Ges. Wien, 1855, p. 13 \ 



Hab. Mexico, Dos Arroyos in Guerrero (//. H. Smith). — Venezuela 1 . 



A single male specimen from Dos Arroyos is referred somewhat doubtfully to this 

 species, inasmuch as the third antennal joint is distinctly truncate at the tip ; otherwise, 

 the description applies fairly well. Both the front and middle metatarsi are wholly 

 yellow, and the hind femora are somewhat redder at the extremity. The second vein 

 arises before the junction of the anterior cross-vein, and the ultimate section of the 

 third vein is shorter than the penultimate section. 



