American Trypanosomiasis 561 



the diagnosis, though if they be found the diagnosis is certain. It 

 is usually much better to inoculate i or 2 cc. of the blood of the 

 suspected case into a guinea-pig and then make frequent exami- 

 nations of its blood. Here, again, the common absence of try- 

 panosome forms from the blood complicates matters. If none can 

 at any time be found, the muscles of the guinea-pig must be exam- 

 ined for the dividing forms of the parasites, which are usually quite 

 numerous. 



Prophylaxis. — As the bugs fly it is somewhat difficult to defend 

 the sleeping patient against them, so long as he lives in a carelessly 

 built and thatched country house. Sulphur fumigation and white- 

 washing may help. Well-built habitations with screened windows 

 and the use of mosquito bars should constitute the best defense. 



Lamus (Conorhinus) Megistis (Burn) 



Patton and Cragg* describe this bug as follows : " Dark brown to black. Pro- 

 notum broadly expanded, with two broad raised red lines extending from the 



Fig. 219. — ^Lamus (Conorhinus) megistis (female), the insect host and dis- 

 tributing agent of Schizotrypanum cruzi (Chagas). X2. 



middle of the posterior border, and a red spot on the postero-lateral angles of pro- 

 notiun. At the anterior border of the pronotum there are six short spines, three 

 <m each side; the most anterior are the longest ^and project on each side of the. 

 eyes; two are situated further back, one on each side of the middle line at the 

 oiigiii of the two admedial ridges; the third spine is situated on a ridge at the 

 junction of the middle and anterior third of the pronotum just above the first pair 

 of legs. Scutellum dark brown with two short red lines converging toward the 

 apex, where they meet; apex red, turning upward and bluntly rounded off. Cor- 

 lum and membrane fuscous, the former with one or more red streaks. Connexi- 

 vum with six well-marked bright red lines, broader in the male; in both sexes the 

 unes extend round to the ventral border. In the male the last segment, except 

 lor a central black mark, is entirely red. Length 30 to 3 2 mm. " 



* "A Text-book of Medical Entomology," 1913, p. 492. 

 36 



