Some three years ago the writer communicated to this Magazine a “ Note on the Genus Stenotheca ” of Hicks, stating that from the appearance of the species, which on this (western) side of the Atlantic had been referred to it, it did not seem to belong to the Pteropoda, but more probably to the Gasteropoda. I also stated that there were two distinct types of shells which had been referred to Stenotheca, one of which by its internal muscular scar and position of the umbo might be compared to Parmophorus, etc.; while the other, represented by a number of minute species, appeared to correspond to the original Stenotheca of Dr. Hicks.