29 



closely united by suture; the recurved spine attached to it is very long and 

 stout ; the lateral claspcrs (7c.) are very long, broad, spoon-shaped. In Petro- 

 phora diversilineata the armature is entirely different. The end of the abdo- 

 men is large, long, square, and membranous. It conceals the armature, and 

 the ends of the claspers are even with the end of the membrane. On 

 removing this, the proportions of the parts arc much as in P. truncata, but 

 smaller; the lateral claspers are narrower and somewhat pointed, and the 

 supra-anal plate is shorter. 



In Glaucopteryx polata, the genital armature is very different from that 

 of Petrophora truncata, so much so as to afford excellent generic characters ; 

 and thqge who with Lederer do not believe in separating the lower genera of 

 the Larentince as done by Iliibner, Stephens, Guenee, and others, would do 

 well to take into consideration the excellent generic characters afforded iu 

 the male genital armature. 



In G. polata, the lateral claspers are very large ; the lower portion is large 

 and spatulate, reaching as far beyond the supra-anal plate as in Petrophora : 

 but the middle is membranous, and, at what would correspond to the upper 

 edge in Petrophora, becomes converted into a chitinous edge, which ends in a 

 long, acute spine; the upper edge of this sharp chitinous portion has a deep 

 sinus at base, and the mucronate tip does not extend as far out as the tip of 

 the spatulate portion. The chitinous portion at the first glance looks as if it 

 were a separate appendage ; but the lower edge on examination appears con- 

 tinuous with the membranous spatulate portion. This chitinous portion does 

 not appear to be represented in Petrophora. The supra-anal plate is smaller 

 than iu Petrophora, and membranous at base and in the middle, the edge 

 forming a broad rim, being solid and chitinous. The recurved spine attached 

 to it is very large. 



In G.sabinii, there is also an upper solid chitinous portion, which is ful 

 and rounded at the end, instead of pointed, and this portion is much larger 

 than the membranous portion, projecting considerably beyond it, the expanded 

 rounded end encroaching on the membranous portion, and much hollowed on 

 the lower edge, slightly sinuous on the upper and free edge. The supra-anal 

 plate is broad and solid, with no median suture, and the end is slightly exca- 

 vated. Thus it seems thai, while very different from G polata, the two 

 species agree in having the upper edge of the lateral claspers solid and 

 chitinous. Though quite different in form from that of G. polata,! should 

 still regard (he differences as subgreneric. 



