ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
279 
for forty-seven generations of self-fertilization (ten years inbreeding of 
the closest kind) there has been no hint of any deterioration. The 
animal has “ a great theoretical gametic purity, greater perhaps than 
any other animal which reproduces sexually.” J. A. T. 
Circus Movements in Slug. — W. J. Crozier and W. H. Cole 
( Proc . Amer. Soc. Zool. in Anat Record , 1922, 23 , 127). In the 
negatively heliotropic Limax, witli non-directive illumination, the 
animal circles continuously toward that side on which the tip of the 
eye-tentacle (including the eye) has been removed. The diameter of 
the circular path varies inversely with the light intensity. The eyes or 
structures in their immediate vicinity are the effective receptors ; upon 
regeneration of the eye after unilateral amputation there is progressive 
return of typical orientation. J. A. T. 
Gastropod Trails in Pennsylvanian Sandstones in Texas. — Sidney 
Powers (Amer. Journ. Sci ., 1922, 3 , 101-7, 3 figs.) Exposures of 
Lower Pennsylvanian sandstones at Shafter show trails which have 
been referred to Trilobites. But they indicate a single foot pressed 
deeply into soft mud and lightly into hard, mica-covered sand. Con- 
centric ridges on either side of the central groove indicate the impression 
of the shell or body on each side of the foot. The probability is that 
the trails were made by Gastropods. J. A. T. 
Arthropoda. 
«• Insecta. 
Mimicry of Ants by other Arthropods. — H. Donisthorpe (Trans. 
Entomological Soc ., 1921, 307-11). Ants are on the whole well pro- 
tected, so it is profitable for other Arthropods to be like them. 1. There 
are “ simple ” Myrmecoids, e.g. the little Locustid Myrmecopliana fallax , 
which are not directly associated with ants. 2. There are Myrmecoid 
Mvrmecophags which feed on ants, e.g. some spiders and tiger-beetles. 
3. There are Myrmecoid Synechthrans which live with ants and feed 
on them, e.g. the jet-black Myrmedonia funesta. 4. There are partial 
Myrmecoid Synceketes, found in association with ants, but not feeding 
on them, e.g. Gonatopus. 5. There are Myrmecoid Synceketes, found 
always with the ants, e.g. the Staphylinid Mimanomma spectrum. 
6. There are Myrmecoid Symphiles or true guests, e.g. Lomechusa. 
7. There are Myrmecoid Entoparasites, which live with ants and lay 
eggs in them or their brood, e.g. the wingless Mimopria ecitomophila. 
8. There are mimetic Formicidse, e.g. Colobopsis truncata and Dolichoderus 
k-pundatus. 9. There are Myrmecophile mimics of Myrmecophiles, 
e.g. Gocinella distincta like Glythra ^-punctata , both found in and about 
the nests of Formica rufa. 10. There are Myrmecophiles like inanimate 
objects, e.g. the guest Ampholis , like a bit of bark. J. A. T. 
Moving Flower-buds tenanted by Apion. — K. M. Heller 
(Entomol. Mittheilungen , 1922, 11 , 52-4, 5 figs.). Description of Apion 
zikani sp. n., the larva of which is found in the calyx of the flower-bud 
