REPORT ON THE TETRACTINELLIDA. iii 
including mountings of Selenka’s interesting species Stelletta nux and Stelletta hacca, the 
systematic position of which has hitherto remained a matter for conjecture, and to my 
friend Professor Haddon, who has generously helped me with specimens and advice, I 
am also under great obligations. Professor Haddon has further done me the invaluable 
service of looking over the proof sheets of the chapters on Morphology. With my friend 
Mr. H. J. Carter I have been in constant communication, and, thanks to the information 
and the numerous specimens I owe to his kindness, I have been able to clear up several 
points that would otherwise have remained doubtful and perplexing. Finally I have to 
express my thanks to Professor Flower and Dr. Gunther for permitting me to consult the 
collections in the British Museum. The plates and illustrations were drawn by my 
friend the well-known artist Mr. T. H. Thomas, R.C.A., who, at considerable personal 
inconvenience and to the neglect of more artistic work, came from Cardiff to reside at 
Dublin for the pm-pose. The figures representing structure were traced by me with the 
camera lucida, and were then drawn by Mr. Thomas direct from the object under the 
microscope ; the tracings being used simply to insure accuracy in scale and outline. 
These drawings are therefore faithful illustrations of what is actually to be seen in the 
preparations they represent, including their imperfections. Perhaps they err a little 
too far on the side of faithfulness, but this I hold is better than introducing corrections 
and interpretations into a picture till it loses its likeness to the original, and becomes a 
subjective rather than an objective representation of the truth as it is in nature. In this 
Report the expression of inferences and deductions has been left to woodcuts and the 
letterpress. 
