TABANUS PAR AND TABANUS T.EXIOLA. 103 



Khartoum on July 19th, and a few days later it was noticed that the majority 

 were not taking their food. They were then nearly, if not quite, full grown, 

 so it was thought that they had buried themselves in the sand prior to 

 pupating. A careful search, however, revealed the fact that they had 

 •disappeared, and it was not until later that mice were identified as the cause 

 of the loss. The two remaining larvae were then killed and preserved. It is 

 possible, therefore, that the larva described below is not quite mature. 



The larva3 of T. tceniola are more active and ferocious than those of T. pcu\ 

 vigorously attacking any other larva with which they may come in contact. 

 "They have not, however, the power possessed by T. par of lying dormant 

 in the soil for at least fifty-seven days if the conditions are unfavourable for 

 their development. 



The egg is spindle-shaped, about 1*75 mm. in length, and, when first laid, 

 white in colour. It becomes darker as the embrj^o within develops. 



The larva when fully extended measures about 29 mm. Colour wdiite to 

 greyish white. Mandibles black. On the anterior third of each abdominal 

 rsegment, except the eighth, is a ring of pseudopods, eight in each ring — 

 two dorsal, two lateral, four ventral — except on the first abdominal segment, 

 where the dorsal pair is wanting. On the second abdominal segment the 

 dorsal pair is very poorly developed. The ventral pseudopods are alwa} s 

 larger than the dorsal. Each pseudopod bears a crown of colourless spines 

 or hooks, and between the pseudopods there are also spines or hooks, often 

 •ilarker in colour, and forming a continuous ring. The anus is situated 

 ventrally at the base of the eighth abdominal segment and is edged with 

 <lark hairs. On either side of the anus is a patch of dark hair, roughly 

 kidney-shaped, and l)eyond each patch, laterally placed on the segment, are 

 two small round spots of dark hair. The siphon-tube consists of two 

 segments, and when exserted is shorter than the eighth segment. The 

 whole surface of the larva is more or less shiny, with varying longitudinal 

 .litriation, the areas bearing very fine stria? being markedly duller than the 

 rest. The prothorax has the dorsal area smooth in the anterior two-thirds 

 <ind rather coarsely striate posteriorly ; the ventral area is almost entirely 

 smooth and divided in two by a median furrow ; the two lateral areas are 

 finely striated in the basal third and more coarsely so in the anterior parts. 

 The mesothorax has the dorsal and ventral areas smooth and shinino: in the 

 anterior two-thirds, and rather coarsely striate posteriorly, the ventral area 

 having no furrow ; the lateral areas are a little more finely striate than those 

 of the prothorax, and there is a rather broad dull non-striated band at both 

 the anterior and posterior margins. Similar dull bands occur on the meta- 

 thorax and the abdominal segments, but completely encircling the segment. 

 The abdominal segments 1 to 7 have the dorsal and ventral areas moderately 

 shining, and the striation is rather coarser and irregular ; the lateral areas 



