April, 1905.] A New Aspidiotus. 325 



Fig. 9. Four tapetal cells, two celled embryo-sac and disintegrating 

 megaspores. 



Fig. 10. Two celled embryo-sac beginning to destroy tapetum. 



Fig. 11. Four celled embryo-sac. 



Fig. 12. Eight celled embryo-sac showing antipodals already settled 

 in pocket. 



Fig. 13. Egg apparatus, conjugating polar nuclei and antipodals. 



PLATE XX. 



Fig. 14. Stamen showing pollen sacs and pollen grains. 



Fig. 15. Older pollen grain with thickened wall. 



Fig. 16. Polar nuclei and a sperin nucleus. 



Fig. 17. Three nuclei fusing to form definitive nucleus. 



Fig. 18. One celled embryo. 



Fig. 19. Two celled embryo. 



Figs. 20-21. Four celled embryos. 



Figs. 22, 23-24. Older embryos. 



Fig. 25. Half grown ovtile showing four celled embryo, endosperm 

 lining, nucellus and inner integument shi"ivelling, and outer integviment 

 developing hard tissue. 



Fig. 26. Flat section of mature seed showing hard integument a-b 

 and outline of embryo imbedded in endosperm. 



Fig. 27. Longitudinal section of a mature ovule through a-b showing 

 cotyledons and plumule. Endosperm around but not between cotyledons. 



A NEW ASPIDIOTUS FROM AESCULUS GLABRA. 



H.\RLAN H. York. 



Aspidiotus (DiaspidiotMs) ohioensis n. sp. Female scale cir- 

 cular, slightlv convex, margin irregular, 1-2 mm. in diameter, 

 dark or dirty gray, exuviae orange red, sub-central and covered 

 with dark excretion. When removed from the bark, the scale 

 leaves a conspicuous white patch. 



Female: Median lobes broad, notched on lateral margin near 

 apex and sometimes notched near the apex on the inesal margin. 

 Second lobes rudimentary, slightly developed on inner-angle, 

 often not present. First interlobular incision shallow, broader 

 than deep, chitinous processes usually fused into a solid process, 

 occasionally furrowed. Second interlobular incision similar to the 

 first, only smaller, the chitinous process seldom furrowed. Some- 

 times there is a very small incision laterad of the second incision. 

 There is usually a small chitinous process at the inner base of 

 each median lobe. A simple and a forked plate, sometimes two 

 to three forked plates laterad of median lobe, one to three forked 

 plates between the first and second incisions and usually one 

 simple and one to three forked plates laterad of second incision. 

 Spines prominent, longer than the plates. On the dorsal surface, 

 one spine at the base of the outer margin of each median lobe, 

 one on each of the rudimentary lobes, one about one-third of the 

 distance from the median lol.)e to penultimate segment and one 

 about the same distance from the penultimate segment. The 

 spines on the ventral surface are shorter than those of the dorsal 



