Some time ago, at the request of Professor Ewart, I undertook an examination of the skull and visceral skeleton of the Greenland shark, Læmargus microcephalus. This I readily consented to do, not only because no attempt had yet been made to describe these structures in this shark, but because they claim careful consideration in view of the recent work by Professor Ewart on the cranial nerves of Elasmobranchs.

In this paper I shall endeavour, without entering into too much detail, to point out some of the more salient features of the skull and visceral skeleton of Læmargus, and to compare them with those of other Elasmobranchs where that seems necessary.

I have made preparations of the above-named structures from the heads of several specimens of Læmargus. The sharks from which the heads were taken were of various sizes, the smallest being about six feet in length, and the largest twelve. As might have been expected, the skeletal parts of these heads are very similar to each other, but I have noticed among the few specimens I have examined points of difference, which make me wish I had a larger number of preparations at my disposal, to enable me to decide the more usual conditions.