new species of CryiHoccridije. 605 



It may, therefore, be reasonably inferred that the habit of 

 Allodape is similar, and that these bees perforate the 

 acacia thorns and use them as their nidus in the same 

 manner as Ceratina uses the bramble stems. The bee 

 that was found might possibly have entered the thorn, 

 tenanted by the ant, mistaking it for that Avhich contained 

 her own nest. 



Genus Ceyptocerus, Latr. 



1. Cryptocerus fervidus. 



Female. — Length 5 2 lines. Chestnut-brown, tlic ab- 

 domen Avith an indistinct pale macula on each side at its 

 base and an ovate one placed obliquely at its apex. The 

 head rather longer than broad; slightly convex above, with 

 the lateral margins raised; the posterior margin of the 

 vertex obliquely truncate ; two minute tubercles on the 

 vertex in front of the truncation ; the flagellum of the an- 

 tennae dark fuscous. Tlie thorax of the same width as the 

 head; the prothorax oblique, with the margins sharp and 

 slightly raised; behind the insertion of the wings nar- 

 rowed, and Avith a short spine on each side of the meta- 

 thorax posteriorly; the scutellum semicircular. The 

 abdomen oblong ; the sides parallel, the anterior margin 

 incurved, Avith the lateral angles slightly rounded ; the first 

 node of the peduncle subquadrate, slightly narroAved pos- 

 teriorly, the second node transverse and Avith a short spine 

 at the anterior angles. (Fig. 1? ? • Ph XI.) 



Hab. — Rio. 



2. Cryptocerus gibhosus. 



Worker. — Length 3 — 3.i lines. Black, ])uncturcd, each 

 puncture with a pale shining seta ; the lateral margins of 

 the head broadly rufo-testaceous anteriorly : also a rufo- 

 testaceous spot at the basal angles of the abdomen. Head 

 large, Avider than the thorax; longer than broad, the 

 lateral margins raised, convex above ; tAvo small tubercles 

 on the vertex. The prothorax transverse, and having a 

 short pale spine at the anterior lateral angles, Avith a trans- 

 A'erse, sharp, raised margin posteriorly ; the mesothorax 

 semicircular ; the metathorax produced laterally and 

 forming a blunt spine, from Avhich it becomes much nar- 

 rower. Abdomen heart-shaped ; tlie nodes of the peduncle 



