614 STAPHYLINID A. 
forms agree in the structure of the oedeagus, I have no doubt they are all one species. 
We figure a female of the typical form from J alapa. 
14. Pederus yucateca. (Tab. XVI. fig. 6.) 
Robustus, niger; elytris quam prothorax vix longitudine, viridescentibus vel cyaneis, fortiter punctatis ; 
mandibulis, prothorace, mesosterno abdominisque segmentis quatuor basalibus rufis ; antennis, palpis 
pedibusque testaceis, antennis medio, femorum apicibus tibiarumque basibus fuscis ; prothorace majore, 
basin versus evidenter angustato. 
Long. 12-13 millim. 
Var. Elytris majoribus, quam prothorax evidenter longioribus. 
Pederus tempestivus, Er. Gen. et Spec. Staph. p. 659, obs. ii. *. 
Pederus rugepunctatus, Chevr., in coll. 
Hab. Mexico (Truqui), Orizaba1, Cordova (Sallé, Hoge), Toxpam (Sallé), Jalapa 
(Hoge), Yautepec (Flohr); British Honpuras, R. Sarstoon (Blancaneaua); GUATEMALA, 
near the city, San Gerénimo, Panajachel, San J oaquin, Cubilguitz, Chiacam (Cham- 
pion); Nicaraaua (Sallé), Chontales (Janson); Costa Rica, Volcan de Irazu 7000 feet 
(Rogers). 
Although Erichson himself regarded ! an example of our P. yucateca as a large variety 
of his South-American P. tempestivus, I have no doubt he was in error in so doing. The 
Neotropical species of this group of Pederus can only be satisfactorily discriminated by 
the assistance of an examination of the cedeagus, but this was unknown to Erichson ; 
and as I fail to trace P. yucateca further to the south than Costa Rica, and as it is appa- 
rently replaced, even in the State of Panama, by an excessively similar but distinct 
species, I think it in the highest degree improbable that it extends to Brazil: thus I 
have little doubt that Erichson mixed more than one species under the name of P. 
tempestivus. I therefore treat our insect as undescribed, and adopt for it a name 
proposed by Fauvel, with which it is labelled in Chevrolat’s and other collections. 
P. yucateca is a variable species. The male usually has the head much broader than 
the female, but this is not constant. In all the Mexican examples the elytra are 
short, as mentioned in the above diagnosis, but in Guatemala they are usually con- 
siderably longer, though this also is variable. The southern examples of the female 
sex usually have the tooth terminating the last ventral plate longer, more slender, and 
spine-like, and with more recurved extremity. The lateral angles of this plate are 
always quite obtuse in P. yucateca. The cedeagus is of complex form, and a little 
asymmetric ; its two lateral lobes are largely developed and of complex structure, the 
central lobe consisting of a long slender process something like a slightly crooked needle, 
and projecting considerably beyond the lateral lobes; it presents no marked difference 
even in the most dissimilar varieties in which I have examined it. 
Our figure represents one of the largely developed males from Jalapa. 
