McLeam — Silurian Arisaig Series of Arisaig, N. S. 139 



Fischer. The size is much smaller than the latter and 

 there is no radial sculpture. The dentition consists of 

 two transverse teeth posterior to the beak and two rows 

 of numerous and much smaller transverse teeth anterior 

 to it. The hinge below the beak is not known. The con- 

 trast in the dentition anterior and posterior to the beak 

 recalls the Triassic to Recent Limopsidse. But there 

 does not appear to be any amphidetic area of the Arcacea 

 type. This genus is named after Eev. David Honeyman, 

 whose name will always be associated with this locality. 

 Genotype: Honeymania planimarginata, n. sp. 



Honeymania planimarginata, new species. 



Outline somewhat mytiliform, with the post-cardinal 

 slope abruptly deflected and descending to a flattened and 

 straight post-cardinal border. The margin is also 

 slightly flattened anterior to the beak. Both adductors 

 well impressed, equal in size, and small. Pallial'line not 

 preserved. A longer expression of this form is named 

 var. elongimarginata, n. var. 



Length 10 mm., height 12 mm. 



Horizon and locality: Rare in the McAdam formation, 

 McAdam Brook and coast sections, Arisaig, N. S. 



Arisaigia, new genus. 



Nuculacea with the dentition of Nucalites Conrad and 

 the clavicle variably developed. Differs in particular 

 from that genus by having radiating striae on the post- 

 umbonal slope. Escutcheon, better defined in later 

 forms, also present. In later Silurian develops scarp or 

 carina, extending from the umbo to the postero-basal 

 angle. The following species are referred to the new 

 genus: Arisaigia postomata, n. sp., Nucula sinuosa 

 Simpson, and Cytherodonf placida Billings. 



Genotype: Arisaigia postomata, n. sp. 



Arisaigia postomata, new species. 



This species differs chiefly from Arisaigia sinuosa 

 (Simpson) in form. It is longer and only slightly con- 

 vergent posteriorly, the post-cardinal margin being 

 almost parallel to the basal margin. The Arisaig form 



