CASE OF PRESUMED PROTECTIVE IMITATION. — SKUSE. 91 



The detailed description is as follows : — 



Animal (fig. 1) — in spirits, with two small left and right mantle 

 lobes, foot in length the shell's diameter, with pedal lini, oblique 

 grooves and caudal raucous pore, apparently surmounted by a 

 horn, sole tripartite. 



Genitalia (fig. 2) — penis broad, much twisted, containing a 

 large blunt papilla, epiphallus more than twice the length of 

 penis ; vas deferens long, bound to wall of atrium. Spermatheca 

 boot-shaped, duct moderately long. Base of vagina black, lobed, 

 containing no follicles. 



Jaw (fig. 4) — rather thin, arcuate, smooth, broad, without 

 central projection. 



In a slightly torn radula (fig. 3) I counted 140 = 4 = 12 = 1 = 

 12 = 4= 140 teeth in 103 rows. Racliidian twice as long as wide, 

 basal plate rather hour-glass shaped, central cusp ovate-lanceolate, 

 projecting half its length over the succeeding plate ; small side 

 cusps with distinct cutting points arise at two-thirds the length 

 of the basal plate. Immediate laterals have the entocone sup- 

 pressed, the ectocone appears as a small hook, the mesocone being 

 broadly ovate. For three or four transition teeth the ectocone 

 rapidly ascends the mesocone, till each of equal size form the 

 bifid cusps of the marginals. These are minute, sinuous, and 

 very numerous. 



On a case op PRESUMED PROTECTIVE IMITATION. 



By Frederick A. A. Skuse. 



(Entomologist to the Australian Museum.) 



[Plate XXII.] 



That wonderful Hepialid, Leto stacyi, Scott, seems to claim a 

 place among those famous examples of a similar nature advanced 

 by Bates, Wallace, and others. The protective resemblances among 

 animals is an established fact, and it is unnecessary to quote classical 

 instances. But I cannot find any reference to such a protective 

 feature as that of a moth which reseml>les in situ an approach to 

 the head of a reptile known to possess an appetite for birds. In 

 the case under notice it may fairly be claimed that such an 

 example exists in nature. 



After consulting my colleagues, by submitting to them photo- 

 graphs of actual specimens in their natural positions — and I am 

 especially indebted to Mr. Edgar R. Waite, whose opinion, from hjs 



