WERNER MARCHAND 119 



pJete circle of hooks. Scattered over the surface of the larva are occasional 

 black hairs. The syphon, when exserted, is shorter than the eighth segment, and 

 bears a number of black hairs. The dark appearance of the larva is due to tiny- 

 dots of pubescence arranged closely together, except on the shiny areas mentioned 

 above. 



The skin of the larva frequently bears scars of old wounds. 



Pupal Case. — (Plate 12, Fig. 137 a, h, c.) Length 20 mm. Color yellowish brown, 

 thoracic tubercles and abdominal spiracles darker, the former bearing hairs. On 

 the posterior third of the second to the seventh abdominal segm.ents inclusive 

 is a ring of backwardly pointing spines, shortest on the second segment and 

 longest on the seventh. The eighth segment terminates in a coronet of six 

 teeth, chestnut-brown in color, darker at the tips, the lateral pair by far the 

 largest, the dorsal and ventral pairs being equal in size. These teeth are ar- 

 ranged roughly in a circle. Ventrally placed to this coronet are two rows of 

 five comparatively thin spines, of varying length, together constituting an inter- 

 rupted transverse row. Dorsolaterally placed to the coronet are two rows of 

 spines similar to the ventral row. 



The dorsum of the abdomen is sometimes clothed with black pubescence 

 arranged in four longitudinal stripes. On the sixth and seventh segments these 

 stripes merge and on the seventh segment the pubescence is confined to the 

 posterior third. The pubescence is wanting on the dorsum of the eighth segment 

 but is present on the venter of the seventh and a small patch is situated immedi- 

 ately below the coronet on the eighth segment. 



The pupa when first formed is yellowish. Later, as the imago develops, the 

 eyes show as dark spots with a greenish tinge and the thorax becomes generally 

 darker. 



Tahanus lasiophthalmiis Macquart. — This species, which is widely 

 spread and occurs, according to Hine, in eastern North America, 

 Columbia, and Chile, has been reared by Hine (1906) from the egg 

 to the adult. The fly is one of the earliest of the genus to appear in 

 the spring, adults having been taken at Columbus, Ohio, as early as 

 May 20, and it is common during the first half of June. The eggs are 

 placed in masses on various plants that grow in low, wet ground, but 

 Hine has not observed them over water. The masses are shiny 

 black when fully colored, rather small for members of the genus, 

 only slightly convex, and accompanied with an unusual amount of 

 cementing material, which nearly obscures the form and arrange- 

 ment of the individual eggs. The mass suggests somewhat a drop of 

 tar or other black substance fastened to the surface of a leaf of the 

 common cattail reed (Typha latifolia), a sedge, or some other plant. 



