276 MODERN CLASSIFICATION OF INSECTS. 
several parasites, including Trichodes apiarius, a species of Anthrax, 
and a large Pimpla. Another species, Megach. senta, places its nests 
on the stems of vegetables. 
The genera Heriades and Chelostoma have the body very long 
and slender, the males having a singular cavity near the extremity of 
the abdomen beneath. They nidificate in posts and rails in a manner 
very similar to the Xylocopz. An interesting account of the habits 
of Chelostoma is published in the first volume of the Entomological 
Magazine, from which it appears that the coverings and partitions 
between the cells are composed of sand. Kennedy (in Lond. and Edin. 
Phil. Mag. Jan. 1837) says that clay is thus used. When at rest, 
they roll themselves into a ball, taking their repose in the bells of 
different species of Campanula. 
The rare and interesting genus Ceratina (fig. 91.13. Cer. cyanea, ° ) 
appears to form the connecting link between the subfamilies Longi- 
labres and Scopulipedes ; its supposed habits and several of its struc- 
tural characters closely resembling those of Xylocopa. M. Spinola 
has published a memoir upon the habits of this genus, in the tenth 
volume of the Annales du Muséum d’ Hist. Nat. de Paris, 1807. This 
author states that the nests are formed in the pith of a branch of 
bramble or briar ; but Messrs. Serville and St. Fargeau consider these 
insects to be parasitic, asserting that they are unprovided with any 
polliniferous organ, and, consequently, that when found in such situation, 
it was for the purpose of placing their eggs in the nests of small Os_ 
mize or Heriades. (Zine. Méth. tom. x. p.181.) Mr. Thwaites has, how- 
ever, confirmed Spinola’s statement, having observed it, as he informs 
me, “ nidificating in bramble-sticks, out of which it scoops the pith, and 
then deposits in them, at regular distances, masses of a coarse sort of 
honey, on each of which a larva may subsequently be found feeding.” 
The fourth subfamily, ScoputipepEs Latr. (or ANTHOPHORIDES), 
derives its former name from the very thick coating of hairs upon the 
hind legs of the females,which constitute the pollen-brushes (/ig.91.8.). 
In general, the basal joint of the posterior tarsi has also its extremity 
angularly produced. These insects have no pollen plates ; the abdo- 
men is also destitute of a ventral pollen-brush. The wings have com- 
monly three perfect submarginal cells; the third joint of the antenne 
is often long and clavate, being very slender at the base; the mouth 
is occasionally very considerably developed. ‘These insects, notwith- 
