208 HEMIPTERA-HOMOPTERA. 
Signoret notices this structure (Ann. Soc. Ent. Fr. 1855, p. 526), but apparently he had 
not seen an example furnished with it: it is probable that every member of the genus 
possesses the appendage at some period or other of its existence, as a circular cicatrix 
or small peduncle, as observed by Signoret, is always present at the apex of the head ; 
in some specimens, however, the character is much more conspicuous than in others. 
1. Diestostemma albipenne. 
Cicada albipennis, Fabr. Syst. Rhyng. p. 62 (1808) *. 
Diestostemma albipenne, Amyot et Serv. Hist. Nat. des Ins. Hémipt. p. 572°. 
Diestostemma albipennis, Walk. List of Homopt. Ins. iil. p. 798 *. 
Tettigonia albipennis, Sign. Ann. Soc. Ent. Fr. 1855, p. 526°. 
Hab. Guatemaua, Cerro Zunil 4000-5000 feet, Las Mercedes 3000 feet (Champion) ; 
PanaMa, Bugaba, David, Volcan de Chiriqui 2000-3000 feet, Tolé (Champion), Chiriqui 
(Mus. Holm.).—Sovuta America 1, Para 3, Brazil 23 4. 
I have retained Amyot and Serville’s name “albipenne” as they give the derivation 
of their generic name and show that it is of the neuter gender ; Walker was in error in 
altering the name to “ albipennis.” 
2. Diestostemma nigropunctatum. 
Tettigonia nigropunctata, Sign. Ann. Soc. Ent. Fr. 1855, p. 527°. 
Hab. Mexico! (Mus. Vind. Ces.). 
This species differs from the preceding in being more elongate and slender, with the 
head longer and smoother, and the forehead more flattened; the pronotum is less 
convex and the humeral angles are somewhat differently shaped. Signoret appears to 
be doubtful as to its right to be regarded as a separate species, but it certainly seems 
distinct. 
8. Diestostemma rugicolle. (Tab. XIII. figg. 1, 1a.) 
Tettigonia nigricollis, Sign. Ann. Soc. Ent. Fr. 1855, p. 525, t. 21. fig. 18 *. 
Hab. Mexico (Sallé1), Atoyac in Vera Cruz (Schumann, H. H. Smith), Misantla 
(F. D. Godman), Teapa in Tabasco (H. H. Smith); Brivish Honpuras, Belize 
(Blancaneaux). 
This species may easily be distinguished from D. albipenne by the much more 
pronounced side-angles of the pronotum, and the large yellowish rugosities on its disc ; 
the appendage of the head is cultriform and flattened at the sides, and it is about as 
long as the head and pronotum together. . 
We figure a specimen from Atoyac and the side of the head of an example from 
Misantla. 
