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- 

 morea 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 ol T- Blaneyi may be analyzed as follows 1 : girdle- 

 covering, like marmorea; 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. Bhineyi f 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 arces- 

 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 Harri man's Point where T. ruber was abundant while 



1 Based entirely on Dr. Hull's descriptions ami figures. The unique specimen 

 is in the U. 8. Nat. Mus. 

 'Series much smaller. 



