66 



different from those occurring elsewhere. One of these, which is 

 undoubtedly entitled to rank as a distinct variety, was first found in 

 1881 ; and no specimens were obtained in any year since until 1887. 

 It seems confined to the lower part of the island, and is least rare along 

 the southern shore. The shell is very large for the species, and is 

 marked by numerous, distinct, dark-green rays. The beauty and com- 

 parative rarity of this form render it one of the most desirable of our 

 shells. I can suggest no reason why it should so widely differ from the 

 ordinary Unio Gom2olanatus found in the same locality. 



It will doubtless be remembered that Mr. Heron included Unio 

 alatus in his list of Ottawa shells, but without stating where it was 

 found. I never observed it until September, 1887, when I obtained a 

 few living examples on the south shore of Duck Island. Mr. Ami 

 informs me that he has taken shells of this species near the same 

 locality, at the mouth of Green's Creek. 



Late in the season a great number of Unio elli2}sis became stranded 

 on shoals opposite Templeton Wharf and perished. Many larger speci- 

 mens than ever previously noted were observed among the dead shells. 

 One remarkably large and beautiful living example of Margaritana 

 undulata was collected in the same locality, as were also a dozen beauti- 

 ful specimens of Unio gracilis. 



A list of the Unionidce found at Duck Island will probably be of 

 interest. The following are the shells of this family which I have 

 observed to occur there : — 



Unio occidens, Lea. Unio gracilis, Barnes. , 



Unio complanatus, Solander. Unio elli2)sis, Lea. 



Unio alatus, Say. Margaritana undulata, Say. 



Unio gibhosus, Barnes. Anodonta Jiuviatilis, Dillwyn. 



Unio borealis, A. F. Gray. Anodonta undulata, Say. 



Unio rectus, Lamarck. 

 The pond on the island teems with the smaller forms of fresh 

 water shells — Sjjhaeria, Amnicolce, Limnceae and Planorbes. On the 

 whole, Duck Island is undoubtedly the richest collecting ground within 

 the sphere of the Club's operations. 



Another locality rich in shells of an entirely different character is 

 Meech's Lake. A few years since two specimens of a very large form 



