THE NAUTILUS. 65 



The most reliable features known to me are the arrangement of 

 the notches and radial canals of the anterior valves (which in mar- 

 rnorea are confined to a central segment of say 100, while in ruber 

 they spread through nearly 180, the limiting pair being obscure) ; 

 and the form of the tegumentum of the mid-valves (which in mar- 

 morea has a rather sharply convex anterior edge, and in ruber con- 

 cave or sinuated). These characters are ascertained in so few speci- 

 mens that I am not sure how constant they are. 



I have no doubt, however, that ruber marmorea, taking the "sum 

 of the characters," are quite valid species as such things go. 



With these conclusions behind us, let us take up the new form* to 

 be discussed. 



The affinities of T. Blaneyi may be analyzed as follows 1 : girdle- 

 covering, like marrnorea; girdle-color, like marmorea; punctation, 

 like ruber; notches and canals (anterior valve,) like marmorea; form 

 of tegumentum (mid-valves,) like ruber. 



I may add that, examining large series for ribbed specimens, I 

 find distinct though slight " ribbing " of the anterior valve in several 

 specimens of ruber but none in marmoreal 



What, now, is T. Blaneyi ? It may be pathological, but nothing 

 suggests it. It may be a unique specimen of an established distinct 

 species, but if so, since said to be conspicuous and occurring in much- 

 worked waters, it must be highly local or excessively rare. It may 

 be a " connected variant " of marmorea, but the intermediate stages 

 of " ribbing " are missing, occuring rather in ruber; it may be a 

 " connected variant" of ruber, but seems closer to marmorea; it may 

 be a "disconnected variant," "sport" or " mutant," which will 

 either become extinct or found a species and which merely happens 

 to come from the ruber end of the marmorea series. Finally, it may 

 be a hybrid, with the ruber tendency to wrinkling (possibly acces- 

 tral ?) intensified by the cross as is not uncommon in such cases. 

 My own provisional judgment would be for the latter. 



While Mr. Blaney was working in Frenchman's Bay I was at 

 work (in the summer of 1899 and 1901) in the next bay west Blue 

 Hill Bay. My richest ground was a small, stony area in about 12 

 fathoms off Harriman's Point where T. ruber was abundant while 



1 Based entirely on Dr. Dall's descriptions and figures. The unique specimen 

 is in the U. S. Nat. Mus. 

 "Series much smaller. 



