358 Mr. E. B. Poulton on distasteful Insects. 
EXPLANATION OF PLATE XVII. 
Leucandra Walfordi, figs. 1-9. 
Figs. 1-4. Four specimens of the sponge, enlarged to the same scale of 
ten diameters. 
Fig. 5. A transverse section of a specimen, showing the thickness of the 
wall and the cloacal cavity. Enlarged ten diameters. 
Fig. 6. A fragment of the inner surface of the sponge-wall, showing the 
irregular disposition of the spicules and traces of canals. En- 
larged sixty diameters. 
Fig. 7. Entire and fragmentary three-rayed spicules of the sponge-wall. 
Enlarged two hundred diameters. 
Fig. 8. Entire and fragmentary four-rayed spicules. Similarly enlarged. 
Fig. 9. Entire and fragmentary rod-like and acerate spicules. Enlarged 
two hundred diameters. 
[The above are from the Marlstone of the Middle Lias at 
King’s Sutton, Northamptonshire. | 
Fig. 10, Detached three- and four-rayed spicules of Calcisponges from the 
Upper Chalk of Croydon and Sutton, Surrey. Enlarged two 
hundred diameters. 
XLVIL.—Mr. A. G. Butler's Remarks upon distasteful 
Insects. By Epwarp B. Poutton, M.A., F.R.S. 
My attention has only just been directed to Mr. Butler’s 
paper in the August number of this Journal. My only object 
in replying to the extraordinary statements and inferences 
therein contained is the enlightenment of readers who may 
mistake the expression of Mr. Butler’s conviction that his 
notes occupy an altogether unique position for a comprehensive 
guide to the literature of the subject. 
Mr. Butler tells us that the attention which a paper of his 
published many years ago “ has since received has been inter- 
esting, as showing how very little has since been done by 
naturalists either to prove or disprove the truth of the theories 
based thereon.” 
From this remark any reader who was not acquainted with 
the subject might reasonably suppose (1) that the theories 
alluded to were thought out by Mr. Butler; (2) that Mr. But- 
ler’s observations formed the first basis on which the theories. 
rested, and that very little or nothing has been added in the 
way of proof or disproof since 1869, when Mr. Butler’s paper 
appeared. 
