76 MR. smith's catalogue of hymenopterous insects 



4. Crematogaster obscurus. C. testaeeus, lsevis et nitidus; thorace 

 strangulato ; metathorace bispinoso. 



Worker. Length \\ line. Dull testaceous; the base of the scape and 

 of the flagellum, the clypeus and mandibles, pale ; the head smooth 

 and shining. Thorax : rounded in front, with a central longitudinal 

 channel ; deeply strangulated in the middle ; the metathorax some- 

 what quadrate, with the posterior lateral angles produced into short 

 spines ; the legs with the apex of the joints, and the tarsi, pale tes- 

 taceous. Abdomen heart-shaped ; the basal node of the peduncle 

 flattened in front, the narrow end above. 



Hab. Borneo (Sarawak). 



5. Crematogaster inflatus. C. niger, laevis et nitidus; parte 

 postica thoracis pallide testacea, inflata. 



Worker. Length 2\ lines. Black, smooth and shining ; the antenna? 

 dark rufo-piceous ; the mandibles striated and ferruginous, their teeth 

 black ; eyes small and lateral, placed about the middle of the head. 

 Thorax : the anterior margin rounded ; the posterior portion inflated 

 into a yellowish semi-transparent bladder-like swelling, divided in the 

 middle by a deep longitudinal depression ; the swollen part not quite 

 so wide as the head ; the apical joints of the tarsi rufo-testaceous. 

 Abdomen heart-shaped ; the peduncle, base, and the apical margin of 

 the first segment, obscurely rufo-piceous. 



Hab. Singapore; Borneo (Sarawak). 



This is one of those singular and anomalous species, which, without any 

 particle of information, derived from observation, puzzle and perplex 

 the naturalist ; what can possibly be the use of the bladder-like ex- 

 crescence on the thorax of this insect, it is difficult to imagine ; to the 

 touch it is elastic, and apparently forms a receptacle for saccharine 

 fluids. With the aid of a microscope, a small circular orifice can be 

 seen at each of the posterior lateral angles of the swollen part, and 

 small crystallized particles are apparent, not only within the orifice, 

 but scattered over the surface of the inflation ; we may, therefore, 

 reasonably suppose that this singular apparatus is for the purpose of 

 elaborating a suitable and necessary aliment for the larvae of this 

 singular insect. 



6*. Crematogaster difformis. C. niger; capite thorace multum 

 latiore ; thorace dilatato et postice profunde excavato ; abdomine 

 cordato. 



Worker. Length 2\ lines. Black ; head very large, twice as wide as 

 the thorax ; the tips of the mandibles, and apical joints of the flagel- 

 lum, dark ferruginous ; the head smooth and shining ; the eyes small, 

 placed laterally about the middle of the head. Thorax : the anterior 

 margin rounded, the sides parallel behind; the metathorax greatly 

 dilated at the sides and above, and with a deep excavation behind ; 



