TRIBE LEPIDOSAPHINI 275 



1. Pygidium of adult female with three 

 pairs of lobes. Type, Mytilaspis phym- 



atodidis Mask. Fusilaspis MacG. 



11. Pygidium of adult female with two pairs 



of lobes. Type, Mytilaspis nivea Mask. 



Albastaspis MacG. 



ii. Adult female with pygidium and segments of 

 preabdomen without subtransverse rows of ora- 

 ceratubae, forming outlets of brevaceratubae ; 



pygidium always with altaceratubae 



Pinnaspis Ckll. 



hh. Pygidium of adult female with median pair of 



lobes adjacent, two lobes together forming single 



semicircular area. Type, Lepidosaphes hemichion- 



aspiformis Green. Hemiaspis MacG. 



ff. Pygidium of adult female with lattice-shaped thicken- 

 ings and with ithree small indistinct groups of gena- 

 cerores; preabdomen and pygidium without or with, 



only few brevaceratubae Ischnaspis Doug. 



ee. Adult female with mesothorax and metathorax separated 

 by deep transverse constriction; pygidium with two pairs 

 of lobes, second pair incised; median incisura with two 



plates. Mytilella Leon. 



dd. Pygidium of adult female with mesal pair of club-shaped 

 paraphyses and with single pair of lobes. Type, Lepidosaphes 



hawaiiensis Mask. Andaspis MacG. 



cc. Pygidium of adult female always without plates cephalad of 

 median pair of lobes, with three pairs of lobes, second pair in- 

 cised; plates of median incisura very small 



Aonidomytilus Leon. 



bb. Pygidium of adult female with median pair of lobes fused into 

 single projection; sometimes with more than five groups of gena- 



cerores. Type, Mytilaspis uniloba Knw Lepidaspidis MacG. 



aa. Pygidium of adult female without groups of genacerores. 



b. Pygidium of adult female always with at least one pair of lobes, 

 c. Pygidium of adult female always with plates, 

 d. Pygidium of adult female never with lattice-shaped thicken- 

 ings. 



e. Adult female with mesothorax and metathorax never sepa- 

 rated by deep transverse constriction. 



f. Pygidium of adult female with lateral margins broad- 

 ly convexly convergent caudad, with caudal end con- 

 vexly rounded, never truncate, with two, rarely three, 

 pairs of lobes; median pair of lobes always different 

 in form and size from the others; scale of male and 

 female not with prominent transverse constrictions, 

 g. Body with metacoria located near middle of its 

 length; portion of body cephalad of metacoria usually 



