77 



either extremity. Arrangement of the rows of pits on the ventral surface 

 approximately the same as on the dorsal snrface ; the remainder of the 

 integument formed of zigzag fokls passing hetween and surrounding the 

 23its. Stigmatic phites {II, ii) semi-lunate, transverse, opposite Coxae 

 IV. Anus a short distance posterior of the level of Coxae IV, 

 elliptical, seven hairs on the edge of each valve. Rostrum {II, I) 

 short, set in a pit near anterior end of tlie body, just anterior of 

 first pair of Coxae ; base rectangular, nearly as wide as long ; 

 mandibles (//, /, ni) witli process of inner apophysis tridentate, outer 

 apopliysis short, with three teeth, the anterior of which is small and sub- 

 terminal ; hypostome notched at its extremity, in the females {II, h), on 

 •eacli iialf. at tlie tips five to seven small teeth m two trans- 

 verse lilies, tJien four strong teeth, disposed two and two, and 

 followed t)y three smaller teeth, below which is a series of teeth becoming 

 smaller and smaller and in three, four, and then five longitudinal rows, 

 wdiicli do not extend to the external l)()rder nor further than the middle 

 of the lengtli of the hypostome ; in the male (//, /) eight small teeth at 

 the tip, folloA\ ed l)y six large teeth in twos, then three small teeth arranged 

 irregularly, below which is a series of small l)lunt teeth as in the female ; 

 palpi elongate, the second article perceptil)ly cylindrical, on their ventral 

 side a few small hairs, and on their dorsal side numerous long 

 hairs with denticles on the convex edges of the hairs, these liairs a 

 little more abundant on the first article than on the second, still less 

 numerous on the third and very few on the fourth, the extremity of 

 wdiich is truncate and a little concave, and bears twelve to fourteen blunt, 

 •cylindrical spines ; four long hairs at the base of the rostrnm, two of 

 which are near the insertion of the ])alpi. Sexual opening in female, long- 

 transversely and narrow, situated between Coxae I, in male half as long 

 as in female, wider, and situated opposite first inter-coxal space. Legs 

 with Coxae slightly striated, those of the first pair a little removed from 

 those of the second, second article cylindrical, almost as wide as long ; 

 the others a little flat dorsoventrally ; the third and fourth elongate, 

 truncate, narrower at the distal extremity, the other two with parallel 

 edo:es, the third lonu'cst, the three others of almost tbe same >ize ; tarsi 

 with the dorsal protul)erance usually indicated by a basilar constriction ; 

 short hairs on all the articles exce])t the coxae. 



FeiiuiJe up to 10 mm. long by (5 mm. wide ; A cry flat when young ; of 

 a thickness in the centre almost equal to the half of its width when 

 it is engorged. The male may reach 5 mm. long by 3 nini. wide, with the 

 same depressions as the female. 



Nympli resembles the adult, hut without the sexual orifice ; anus wider 

 than in larva, five to seven s])iiies on each valve. Mandibles like those of 

 adult ; hypost' me (//, /) with five to eight small teeth at tip on each half, 

 then five large teeth, followed l)y a series of small blunt teeth, gT(^wing 

 smaller jio^teriorly and in rows of three, then four. 



Larva (/, (unengorged ), oval in outline, l)roadly rounded l)ehind and 

 niore narrowly rounded in front ; ().()() to 0.70 mm. long by 0.50 mm. 

 wide ; fiattened, with marginal and central ]3art of dorsal surface slightly 

 raised ; light yellowish or greyish in colour, becoming nearly translucent 

 at the margin, from which colourless lines extend toward the centre ; a 

 lighter shield-shaped area on the dorsal surface over the rostrum ; surface 

 of body with fine parallel transverse and slightly undulating striae ; no 

 pits : edge of body with a marginal row of short folds ; numerous large. 



