426 Mr. T. D. A. Cockerell on 



pear-shaped, and bears on the outer margin a small tuft of 

 fine setae at the centre and another at the extremity ; the 

 inner margin is without setae ; the peduncle appears to have 

 coalesced with the sixth segment of the pleon. 



EXPLANATION OF PLATE XVIII. 



Hyalella mihiwaka. 



Fig. 1, Side view of male, X 19. 



Fig. 2. Upper antenna, X 45. 



Fig. 3. Lower antenna, X 45. 



Fig. 4. Maxillipedes, X 45. 4«. Inner lobe, x 120. 46. Extremity, 



X 120. 



Fig. 5. First gnathopod, X 45. 



Fig. 6. Second gnathopod of male, X 45. 



Fig. 7. Second gnathopod of female, X 45. 



Fig. 8. Pleon, x 45. 



Fig. 9. First uropod, X 45. 



Fig. 10. Second uropod, X 45. 



Fig. 11, Third uropod, X 45. 



Fig. 12. Telson, X 85. 



LXVI. — New Coccidte from Mexico. By T. ^ D. A. 

 Cockerell, Entomologist of the New Mexico Agricultural 

 Experiment Station. 



The Coccidae herein described were collected in Mexico in 

 1897 by Mr. A. Koebele and Prof. C. H. T. Townsend, and 

 sent to the U.S. Department of Agriculture. I am much 

 indebted to Dr. L. O. Howard, the Entomologist of the 

 Department, for the opportunity of studying and describing 

 these insects, which prove to be many of them of extreme 

 interest. 



It is proper to state that Mr. Koebele's expedition was 

 made at the expense of the government of the Sandwich 

 Islands, while Prof. Townsend's collecting was done in the 

 service of the United States. 



POROCOCCUS, gen. nov. 



Allied to Solenophora. Female with antennae and legs. 

 Antennae 6-segmented, the last segment long. Caudal 

 tubercles not much produced. Anal ring with 6 bristles. 

 Insect contained in a black scale, which has an orifice at the 

 hind end. Embryonic larva with rows of spines as in Erio- 

 coccus &c. 



Type P. tinctorius. 



