The Theory of Mimicry and Mimicking Theories. 43 



It is thus seen that Hamingia is really intermediate in its 

 combination of characters between Bonellia and Thalassemia. 



Owing to their not having known the frontal hood or pro- 

 boscis of Hamingia, Koren and Danielssen have somewhat 

 overestimated the closeness of its relationship to Bonellia. On 

 the whole it may be said that Hamingia has in internal organs 

 a closer resemblance to Bonellia, in external shape and cha- 

 racters a closer resemblance to Thalassema. 



The feature in which it is quite peculiar is in the absence 

 of genital setse in the female and the correlated existence of 

 one or of two prominent papillae which carry the genital pore 

 or pores. 



Summary. — The new facts which have been above recorded 

 additional to the observations of Koren and Danielssen and 

 Ilorst are briefly as follows : 



1. Hamingia arctica occurs on the Norwegian coast in lati- 

 tude 60°, and at the comparatively small depth of 40 fathoms. 



2. Hamingia has a frontal hood or proboscis resembling 

 that of Thalassema, which is easily broken off as in Thalas- 

 sema and Echiurus. 



3. The corpuscles of the perivisceral fluid of Hamingia 

 arctica are coloured red by haemoglobin. 



4. The male of Hamingia is a diminutive parasite living 

 upon the female, as in the case of Bonellia ; it is provided 

 with a pair of large genital setae, although such setae are absent 

 in the female. 



5. Though usually there are two, yet there may be only one 

 uterus and one genital pore, as in Bonellia. 



V. — Tlie Theory of Mimicry and Mimicking Theories. 



By W. L. Distant. 



In the last issue of this Magazine (vol. x. p. 417) an article 

 on the interesting subject of u Mimicry between Butterflies 

 of Protected Genera," by Mr. K. Meldola, appears to be 



inspired by two short opinions of my own published else- 



where ; and as the author has done me the honour of subjecting 

 those views to a critical and somewhat trenchant analysis, it 

 becomes necessary to point out that some of his strictures (in 

 the present absence of supporting facts) appear to belong to 

 the armoury of what may be called " forensic biology," and 

 represent arguments which may ultimately prove to be both 



