Tabanidae. 89 



fioin tlie apex — ; the maxillary palpi generally lie down along the 

 front side of the proboscis, two-jointed, the second joint a little curved. 

 Labriim and hypopharynx lancet-like blades of the same length as 

 the proboscis. In the male the proboscis is a little more slender, the 

 mandibles wanting, and the second joint of the maxillary palpi porrect, 

 nearly cylindrical or a little thickened, long pyriform. Thorax nearly 

 quadratic; abdomen somewhat flat with seven distinct, not transformed 

 segments. Posterior tibiæ with two apical spurs. Wings with dark 

 spots, consisting as a rule of a long basal spot at the anterior margin, a 

 niiddle cross-band and an apical spot; in the males the dark markings 

 are as a rule more extended than in the females. When at rest the 

 wings are borne half open, a little more so than in Tabanus. 



With regard to the metamorphosis of Chrysops I must chiefly 

 depend on the observations of others, as I only have examined the 

 pupæ, and therefore take the descriptions of the larvæ and the eggs 

 from other works. The larvæ of C. coecutiens L. is described by 

 Beling (Verh. zool. bot. Geseli. Wien, XXXVIII, 1887, 1). It is elongated, 

 cylindrical, greenish yellow; it is, as the Tabanus larva, finely striated 

 longitudinally. The head is small. The body consists of twelve seg- 

 ments. On the ventral side the fiflh to the eleventh segment bears 

 eaeh four strong, tubercular swellings placed in a transverse row 

 (Kriechschwielen); together they form four longitudinal rows. The last 

 segment is conical, truncate, narrower than the preceding with a very 

 deep, longitudinal impression in the end in the center of which is a 

 small, conical spiracle bearer, vertically cleft at the apex. On the 

 ventral side, at the base of the last segment lies the anus as a longi- 

 tudinal spht. The length of the larva is 10 to about 14 mm. in relation 

 to its contraction. — The pupæ are slightly curved, almost straight, 

 the sheaths of the legs and wings reach to the posterior margin of 

 the first ahdominal segment. The abdominal segments, except the 

 tirst, are each provided with a girdle of strong bristles at their hind 

 margins, the bristles being largest on the posterior segments. The 

 apex of the abdomen bears six spines, four placed in a curved line 

 above, and two below, the two lateral above being the strongest, and the 

 two median the smallest. At the anterior margin of the thorax tliere 

 are two large, somewhat ear-shaped prothoracic spiracles, and on the 

 sides of the abdomen there are seven small, the first lying just at the 

 hind margin of the wing-sheath. On the head the sheaths of the 

 antennæ are lying in front, directed outwards to each side; between 

 the bases of these, a little downwards, there are four (sometimes only 

 two) somewhat transverse tubercles lying in a curved line; behind the 

 bases of the of antennal sheaths there are on each side two small 



