306 



THE AMEBIC AN NATURALIST [Vol. XLIV 



gum to the subfamily Coronulinee as defined by Gruvel, 2 being 

 most closely related to the genera Tuhicinella Lam., which lives 

 on the skin of whales, and Stephanolepas Fischer, a barnacle 

 which lives imbedded in the plates of Thalassochelys imbricata. 

 Both of these have the wall more or less tubular and conspicu- 

 ously annulated externally. In Stomatolepas the wall is de- 

 pressed and broadly bowl-shaped, and covered externally with 

 a mass of thin-walled cells. 



Henry A. Pilsbry. 



THE AGE OF SPEED SIRES 

 The contribution by Professor F. R. Marshall in The Ameri- 

 can Naturalist for January, 1909, on the age of speed sires, 

 escaped my notice until recently called to my attention. In that 

 article Professor Marshall refers to the fact that I found the 

 average age of trotting sires to be 10.43 years, and that by ta- 

 king all sires in four generations of ancestors of 2 :10 trotters I 

 found the average age at approximately 14 years. 



Professor Marshall objects to this comparison as not being a 

 fair one on the ground that by going back four generations 

 from our 2:10 trotters we go back into the formative period of 

 the breed. This formative period, he asserts, followed the descent 

 from Hambletonian 10, foaled in 184!). and involved his sons, 

 which were used largely in the stud until old age. This he holds 

 produced an abnormal number of old sires at that period of his- 

 tory, and that by including them in my tables I was drawing 

 unwarranted conclusions from what was a mere incident. This 

 he reinforces by showing that the immediate sires of 242 trotters 

 in the 2 :10 list were of the same age that I found for the normal 

 breeding age of 1,000 cases. 



In this matter Professor Marshall labors under a misappre- 

 hension. The average age of 10.43 years for sires which I found 

 was the average as it existed in the "formative period" from 

 1840 to 1890. The "Register" from which they were taken was 

 published in 1892 and contained an alphabetical list of all stand- 

 ard horses from the earliest date up to immediately before 1892. 

 The tabulation was taken alphabetically from the index and the 

 10.43 is an accurate representation of what occurred when the 

 crrandsires. ureat-^randsires and .<rreat-.irreat-grandsires of our 

 2 :10 trotters were living and being bred. 



There is, in this matter, food for profound thought, and, with- 

 2 " Monographie des CirrhipMes on Thecostraces, " pp. 9, 270. 



