ENTOMOLOGY 857 
stalk. Among the African species of which Pomeroy has described the pupae, S. alcocki var. 
coalitum Pomeroy (1922, Bull. Ent. Res., XII, 4, p. 460, Pl. XVI, fig. 1), of Ibadan, Nigeria, has 
somewhat similar respiratory filaments, although the number of branches is larger (10). It is 
rather remarkable that Pomeroy regarded the long-stalked filaments of this form as perhaps the 
result of malformation. This is certainly not the case for the Liberian species here described, as I 
have examined many specimens and found them all alike. 
In 1907, Roubaud described the early stages of an African black-fly which 
he referred to H. damnosum, although he bred no adults from the pupae. He 
found both larvae and pupae near Brazzaville, French Congo, attached to aquatic 
plants in torrents running to the Stanley Pool. The larvae were provided with 
three rectal pennate gills, which could be expanded or retracted at will. Such 
retractile gills Roubaud regarded as an adaptation to aquatic life in the very 

Text Fiaure 6. — Dorsal and ventral aspects of pupa and cocoon of 
Simulium, species, at Gbanga, Liberia 
hot regions of Central Africa. The pupae he described as sheltered within a 
cocoon of the usual trumpet shape; the eight respiratory filaments start from 
three main stalks, of which the outer and inner ones are bifurcate once, while 
the middle one is bifurcate twice and at different levels. Although the deserip- 
tions are very brief, I am inclined to believe that Roubaud dealt with larvae and 
pupae identical with, or at least very similar to, those I here describe from Liberia. 
H. H. King (1909) described and figured larvae and pupae from Abu Hamed, 
Anglo-Egyptian Sudan, which he claimed to be those of #. damnosum, although 
he evidently bred no adult flies from them. The short description of the larva 
mentions no characters of specific value and only the general appearance can be 
gathered from the figure.'_ The pupa, he says, ‘‘is pale chestnut brown in colour 
1 “The larva resembles in shape and general appearance the Nimitti larva [Simuliwm griseicollis 
Becker], but can be distinguished from it by its relatively larger size and darker colour. A dark pig- 
mented patch is usually present on either side of the first thoracic segment. Length about 6 mm.” 
The description of the larva of S. griseicollis also is couched in very general terms, mentioning hardly 
anything beyond peculiarities common to nearly all simuliid larvae. 
