HETARINA. 31 
7. Heterina titia. (Tab. IIT. figg. 2-15.) 
Libellula titia, Drury, Ill. Exot. Ins. ii. p. 83 and index, t. 45. fig. 5 (entire insect) (1773) *. 
Agrion titia, Drury, Westwood’s edit. ii. p. 94, t. 45. fig. 5 (1837) *. 
Calopteryz titia, Burm, Handb. d. Ent. ii. p. 826 (1839) °; Rambur, Névr. p. 227 (1842) *. 
Heterina titia, Selys, Syn. Calopt. p. 43 (1853) >; Monogr. Calopt. p. 138 (1854) ° , Bull. Acad. 
Belg. (2) xxxvi. p. 613 (1873) "3 Walker, List Neur. Ins. Brit. Mus. iv. p. 630 (1853) °; 
Hagen, Syn. Neur. N. Am. p. 61 (1861) >. Proc. Bost. Soc. Nat. Hist. xviii. p. 24 (1875) °; 
Kirby, Cat. Odon. p. 106 (1890) ny 
Heterina titia, race? bipartita, Selys, Bull. Acad. Belg. (2) xxxv. p. 481 (1873) ”. 
Heterina bipartita, Hagen, Proc. Bost. Soc. Nat. Hist. xviii. p. 24 (1875) ; Kirby, Cat. Odon. 
p. 107 (1890) *; Carpenter, Journ. Inst. Jamaica, ii. p. 261 (1896) ”. 
Hab. Unrrep States, Florida, on the Caloosahatchie River between Fort Thompson 
and Fort Daneau (Johnson, coll. P. P. C.: 1 3), Texas, probably near the Nueces 
River (colls. A. N.S. & P.P.C.: 93,42), Waco 10 and San Antonio !° (fide Hagen). 
—Me_xico 5, Nuevo Laredo in Tamaulipas (Barrett, coll. P. P. C.: 6 &,2 2), Atoyac 
(Schumann: 5 9; H. H. Smith: 3 ), San Lorenzo, Cordova (Zrujillo: 2 2), Teapa 
in Tabasco (H. H. Smith: 6 9); Brivisu Honpuras (Blancaneaur: 6 6,3 2), Rio 
Sarstoon (Blancaneaux : 2 3); GUATEMALA, Cahabon [1 ¢ |, Teleman [19 ¢, 2 2, one 
pair of these in copuld}, and Chacoj [7 ¢, 3 2], all in Vera Paz (Champion); 
Honpuras (coll. McLachlan: 1 ¢,1 2), Bay of Honduras 1; Nicaraaua, Chontales 
(coll. McLachlan, types of H. bipartita: 2 3 ).—West Iyp1ss, Jamaica". 
H. bipartite was doubtfully regarded as a race of H. titia by de Selys!*, and as a 
distinct species by Hagen }° and Kirby ™. Its differences (3) from the latter were 
thought to be: the smaller pterostigma, hardly surmounting one cell, and the much 
less extension of the dark brown coloration, especially on the hind wings. These 
supposed peculiarities are negatived by the following facts :— 
The present series contains individuals of typical H. bipartita in which the pterostigma 
surmounts two cells and is therefore as large as in typical H. titia; also individuals of 
H. titia in which the pterostigma is of varying size, from two cells, to 13, 1, or § a 
cell, or entirely absent (in 3 ¢ from Chacoj and 1 ¢ from Rio Sarstoon). A complete 
and gradual transition exists in the amount of brown on the wings from the condition 
in the H. bipartita-type to a condition even still more extended than that of the 
H. titia-type. No structural difference has been found between the two forms, and 
H. bipartita is, therefore, merely a synonym of H. titza. _ 
The above facts with regard to the pterostigma amply confirm the suggestion of 
de Selys7: “ On peut présumer d’aprés cela et jusqu’a ce qu’on ait pu examiner un 
nombre suffisant d’exemplaires en bon état, que la pterostigma varie chez cette espéce 
comme chez l’occisa et ses races ou variétés.” 
The occurrence of H. bipartita-type, of H. titia-type, or of any of the intermediate 
forms which completely connect them, is not correlated with geographical isolation, 
