reception of all those species the males of which have two brands upon the interno-median area of primaries. For this latter group he coins the name Stictoplæa. These brands in the Stictoplæa he conceives are for purposes of strigillation. Then follows a list containing the species under each genus of the series contained in the British Museum Cabinets, with notes of elucidation.
March 7, 1878.—Dr. Gwyn Jeffreys, Vice-President, in the chair.
Mr. Charles C. P. Hobkirk, of Huddersfield, was ballotted for, aud elected a Fellow of the Society.
Prof. Ray Lankester exhibited and made remarks on a valuable series of fossil Walrus tusks (Trichecodon Huxleyi) from the Suffolk Crag, sent to him for examination by Mr. J.E. Taylor, of the Ipswich Museum.
Mr. Rich exhibited some examples of a new variety of Helix virgata forwarded to him from Ireland.
The first zoological paper read was "On some New Species of Nudibranchiate Molluscs from the Eastern Seas," by Dr. Cuthbert Collingwood. The author remarked that zoologists and voyagers who pav but brief visits to the tropical coasts are less likely to obtain new or interesting forms of the Nudibranchiates than are residents searching carefully within limited areas. Thus he accounts for Sir W. Elliot's Madras, and Kelaart's Ceylon, gatherings surpassing expeditions fully equipped for collection. The, gay colouring of the group is equally found on our own shores, less climatically favoured, as on those of the tropics. Seasonal aud other influences probably have much to do with abundance or scarcity of species, even in a given locality, where previously known to exist. Dr. Collingwood noticed some curious instances in which specimens isolated in a dish of sea-water spontaneously, and very neatly, amputate the region of their own mouths. He then described the following sixteen new species, and exhibited coloured drawings from Nature, showing the animals in the expanded and contracted conditions:—(1) Doris pecten, (2) D. crescentica, (3) Chromodoris iris, (4) C. Bullockii, (5) C. aureo-purpurea, (6) C. tumulifera, (7) C. tenuis, (8) C. funerea, (9) C. Alderi, (10) Albania formosa, (11; Triopa principis-Walliæ, (12) Trevelyana felis, (13) Doridopsis arborescens, (14) Phyllidis spectabilis, (15) Freyeria variabilis, (16) Bornella marmorata.
In the absence of the author, Dr. Patrick Manson, Dr. Cobbold communicated a paper "On the development of Filaria sanguis-hominis, and on the Mosquito considered as a Nurse." He pointed out that development cannot progress far in the host containing the parent worm; that the embryo must escape from the original host; and that in the case in question the mosquito is found to be the nurse. The latter term, "nurse," he employed
