3io 
Psyche 
[December 
eight (Fig. i, Y). At prophase (Fig. 2) the X chromosomes are 
greatly elongated and are associated with a nucleolar organizer. 
At late anaphase (Fig. 3) the chromatids of the sex chromosomes are 
still in contact on the metaphase plate while the fully disjoined 
autosomes have reached the poles. In both sexes a large heterochro- 
matic irregular-shaped body is always visible in the nucleus during 
interphase. However, it is not clear whether this represents only one 
or both sex chromosomes. Both the autosomes and the sex chromo- 
somes have a fuzzy appearance during all stages of division, suggesting 
that some genetic activity may be in progress even during cell division. 
The polytene chromosomes of the salivary gland, gut, and Malpighian 
tubules were checked and found unsuitable for detailed analysis. 
Zonosemata Benjamin 
Spilographa Loew (in part), 1873, Smith. Misc. Coll. 256: 244-, 336. 
Zonosema Coquillett, 1899, Jour. N.Y. Ent. Soc. 7: 261. 
Phorellia Hendel (in part), 1914, Abh. u. Ber. Zool. Mus. Dresden (1912) 
14: 28. 
Zonosemata Benjamin, 1934, U.S. Dept. Agri. Tech. Bull. 401: 17-18. [Type 
of genus, Trypeta electa Say, location unknown, apparently lost 3 ; type 
locality: Indiana]. — Aczel, 1951, Acta zool. Lilloana 9: 214. — Aczel, 
1954, Dusenia 5 : 152-153. 
Further details on the nomenclatorial history of this genus may 
be found in Benjamin (1934) and Stone (1951). 
generic diagnosis. Zonosemata may be distinguished from other 
members of the tribe Trypetini by the following combination of 
characters : 
1. Predominantly yellow with black maculations, a cream colored 
notopleural stripe and brown crossbands on the wing. 
2. Dorsocentrals located closer to a line drawn between postalars 
than to anterior supraalars. 
3. One pair of well developed outer scapular bristles, inner pair 
absent or if present (rarely) then minute. 
4. Sex chromosomes diffuse, much elongated, heterochromatic and 
heteropycnotic ; autosomes very small and diffuse. 
5. Surstyli blunt, short and broad; not greatly elongated beyond 
prensisetae. 
6. Usually four pairs of lower fronto-orbital bristles. 
7. Dorsum lacking pollinose microtrichia. 
8. Larvae with minute poorly sclerotized stomal guard hooks. 
3 Although no type could be located for electa, Say’s original description 
is clear enough to leave no doubt as to the identification of the type species. 
A neotype was not designated pending a more thorough search for the type. 
