TRIBE DIASPIDINI 311 



mm. Pygidium with caudal margin with 

 deep pygidial incision, median pair~nf- 

 lobes located in incision and not or 

 scarcely projecting beyond its sides. 



Type, Chionaspis flava Green 



Ametrochaspis MacG. 



11. Pygidium with anus distinctly farther 

 caudad than vulva. 



m. Pygidium with caudal margin with 

 deep pygidial incision; each median 

 lobe as large as or larger than mesal 

 lobelet of second lobe; median pair of 

 lobes subadjacent. Type, Chionaspis 

 citri Comst. Prontaspis MacG. 



mm. Pygidium with caudal margin convex; 

 each median lobe distinctly smaller 

 than mesal lobelet of second lobe; me- 

 dian pair of lobes distinctly farther 

 apart than width of median lobe. 



Type, Chionaspis dentilobis Newst 



Remotaspis MacG. 



j. Pygidium with one or two pairs of lobes, 

 k. Pygidium with two pairs of lobes. 



1. Pygidium with anus located distinctly 

 cephalad of vulva, near cephalic margin. 



m. Pygidium with two pairs of large 

 prominent lobes; oraceratubae of 

 brevaceratubae in rows. Type, Chion- 

 aspis distorta Newst 



Asymmetraspis MacG. 



mm. Pygidium with two pairs of minute 

 inconspicuous lobes; oraceratubae of 

 brevaceratubae not in rows, promiscu- 

 ously arranged. Type, Protodiaspis 

 lobata Ferris O'bluctaspis MacG. 



11. Pygidium with anus located distinctly 

 caudad of vulva, near caudal margin. 



. Type, Pseudodiaspis condaliae Ferris 



Situlaspis MacG. 

 kk. Pygidium with single pair of lobes. 



I. Pygidium with caudal margin uniformly 

 convex. Type, Chionaspis (?) hikosani 

 Kuwn. Kuwanaspis MacG. 



II. Pygidium with caudal margin with dis- 

 tinct pygidial incision. Type, Diaspis 

 pugionifera Lindgr Inciaspis MacG. 



