TABLES OF MANSONIA 503 



cussed here in detail. Edwards has recently done excellent work in this direc- 

 tion with the Old World forms, particularly the African ones (The African 

 species of Culex and allied genera, Bull. Ent. Ees., ii, 241-368, 1911 ; A synopsis 

 of the species of African Culieidse, other than Anopheles, BuU. Ent. Ees., iii, 

 1-53, 1913). Ifeveu-Lemaire, in an article on the receptacula semiais of 

 female mosquitoes (Sur les receptacles s6minaux de quelques culicides, Bull. 

 Soc. Zool. Prance, xxvii, 172-175, 1902), indicated two of these organs for the 

 genus Mansonia, basing his statement upon an examination of the African M. 

 uniformis. Dyar and Enab found that the type species of Mansonia (titillans) 

 has three receptacula semiais, as do the species properly associated with it, and 

 have indicated that the forms with two receptacula should be segregated imder 

 Mansonioides (Ent. News, xxi, 363, 1910). This course has been adopted by 

 Edwards (Bull. Ent. Ees., ii, 351, 353, 1911). It should be noted that while 

 in such forms as Mansonia fasciolatus and M. perturhans the three receptacula 

 are of nearly equal size, in M. titillans one of them is very much smaller, thus 

 representing a step in the direction of Mansonioides. Edwards has recently 

 shown that the larva of Mansonioides africanus (Theo.) is very similar to that 

 of Mansonia (Bull. Ent. Ees., iii, 377, 378, 1913) and it is possible that further 

 studies will result ia the fusion of these two genera. 



The species typified by Mansonia perturbans, to which group belong fascio- 

 latus and arribalzagw, deposit the eggs in boat-shaped masses on the surface of 

 water and resting agaiast the stems of aquatic vegetation. The eggs are laid in 

 swamps where there is abundance of vegetation. The larvae on hatching descend 

 to the bottom, enter the mud, and become attached to the roots of aquatic plants 

 by their air-tubes. They cut the surface of the roots with their sharp tubes and 

 obtain their supply of air from the vascular tissue of the roots. The develop- 

 ment is slow, and the larvae never come to the surface. The pupae also remain 

 attached to the roots by their breathing tubes which are modified for this pur- 

 pose. The exact manner of the emergence of the imago has not been described. 

 The adult females bite severely. They fly to a considerable distance from their 

 breeding-places. In temperate latitudes there is but a single generation in the 

 year, the winter being spent in the larval state, partly grown, at the bottoms of 

 swamps. 



The species typified by Mansoma titillans have very similar habits, the larvae 

 likewise attaching themselves to the roots of aquatic plants by the air-tube. The 

 egg-laying of this group has been observed by H. W. B. Moore, too late for 

 inclusion in this work. 



Tables of the Species, 

 adults, steucttjee and colobation. 



1. Tarsi pale, without white rings oohropus Dyar & Knab (p. 504) 



Tarsi with white rings 2 



2. Hind tibia with a white ring beyond the middle 3 



Hind tibia without white ring 4 



3. Hind tarsi with white ring at middle of first joint. . . perturbans 'Wlalker (p. 505) 

 Hind tarsi without such a white ring nigricans Cociuillett (p. 511) 



4. Wing-scales all blackish 5 



Wing-scales peppered, blackish and whitish " 6 



5. Lateral abdominal spots silvery coticula Dyar & Knab (p. 515) 



Lateral abdominal spots not silvery fasciolatus Lynch Arribaizaga (p. 512) 



6. Color predominatingly dark titillans Walker (p. 516) 



Color predominatingly yellowish fiaveolus Coquillett (p. 521) 



ADULTS, MALE GENrTALIA. 



1. Basal lobe of clasp moderate, without apical spines. . perturbans Walker (p. 507) 

 Basal lobe of clasp long, with apical spines " 2 



2. Fork of clasp-filament subbasal, slender titillans Walker (p. 5185 



Fork of clasp filament medial, thick fiaveolus Coquillett (p. 523) 



