212 Dr. F. C. Wellman on 



tenance of this is the establishment of their primary hcxa- 

 merism, an*] unless verj weighty evidence to the contrary 

 should be forthcoming this must now be regarded as 

 accomplished. The facts in support of the relationship may 

 be summarized as follows : — 



1. The Rugose corals and the Zoanthid actinians have both 

 a primary hexamerism. 



2. The septa in the Rugosa and the mesenteries in the 

 Zoanthese are added in bilateral pairs at only one region, a 

 vertical zone within the primary exocoeles, there being four 

 such regions — middle and ventro-lateral chambers — in the 

 Rugosa, and two — ventro-lateral chambers — in the Zoantheae. 



3. The septa in the Rugosa and the mesenteries in the 

 Zoanthese are never polycyclic, as in modern corals and 

 ordinary actinians ; at most there are only two cycles of 

 septa, large entosepta and small exosepta, disposed in such 

 a manner as could only have been produced in polyps with 

 a mesenterial arrangement similar to that of the Zoantheaj. 



4. The presence of a ventral directive fossula in the 

 Rugosa, usually persisting in the fully developed and other- 

 wise perfectly radial calice, can be explained by the 

 occurrence within the living rugose polyp of a single ventral 

 siphonoglyph or gonidial groove, such as is characteristic of 

 zoanthid polyps. 



XXXV. — Xotps on the Ilahits of Tsetse-Jlies. 

 By F. Ckeighton Wellmax, Benguella, West Africa. 



Having recently had opportunity to make some observations 

 on tsetse-flies in the Esupua " fly- belt," about thirty-tive miles 

 inland from the seaport town of Benguella, West Africa, [ 

 present here some of my findings. Our knowledge of these 

 flies is as yet very far from complete, and first-hand observa- 

 tions, including mention of the date, habitat, and species 

 studied, should be recorded. 



The following notes were a few of them made in November 

 1904, but most of them date from October 28tli and L'yth and 

 November 'Jth and 10th, 1905. The Esupua ''fly-belt" is, 

 as I have said, about thirty-five miles inland from the port of 

 Benguella (13° S. on the west coast of Africa) and twenty 

 miles from the city of Catumbella. The fly studied by me is 

 a subspecies of Glosstna j'alj'ali't--, Robineau-Dcsvoidy, which 



