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 MARINE ZOOLOGY kled, with aperture approximately semi- circular and a more or less pronounced prominence underneath. The connection with adjacent zooecia is not continuous, but vacant spaces occur at intervals around the margin. Common upon scallop shells, etc., from deep water. Hastings. PORINID^ 43. Porina tubuiosa, Norman. Zooecia ovate in the lower half, the upper part narrowed and curving upwards, with a circular aperture. A little below this there is a tubular pore, and elsewhere the wall is pitted with pores. Upon old shell of Cardium norvegicum ; rare. Hast- ings. 44. Lagenipora socialis, Hincks.* Hastings (Miss Jelly). Myriozoid^ 45. Schizoporella unicornis, Johnston. Encrusts rock at low tide ; zooecia rather large, square to sexagonal ; aperture semi- circular with sinus in the lower lip. Be- neath there is usually a short blunt spine, and in either or both upper corners an avicularium. In one instance noted, an avicularian zooid had usurped the position of an ordinary zooid, the aperture of the latter appearing as a minute pore immedi- ately above the mandibular apparatus of the former, the zooecium remaining of the normal size but with partial obliteration of outline. Common. Hastings. 46. Schizoporella vulgaris, Moll.* Hastings. 47. Schizoporella simplex, Johnston. Encrusting old shells. Zooecia ovate ; aperture elevated and with a sinus to the primitive orifice, the matured one being circular. Beneath the aperture, and gener- ally confluent with it, is a blunt promin- ence. Ooecia with a few irregular spiny protuberances. Not very common ; from moderate to deep water. Hastings. 48. Schizoporella linearis, Hassall. Encrusting old shells. Zooecia oblong, arranged in lines ; aperture round, with a small sinus in the lower margin ; front wall with pores. Upon one or both sides of the aperture, and a little below, is placed an avicularium pointing towards it. Common. Hastings. I 89 49. Schi-zoporella bi-aperta, Michelin. Zooecia more or less oblong ; aperture round with a sharp sinus below ; front wall plain. Upon one or both sides of the aperture there is a considerable prominence surmounted by an avicularium. Upon Pecten operculars, etc. From moderately deep water ; rather rare. Hastings. 50. Schizoporella auriculata, Hassall. Forming round patches upon shells, stones, etc. Zocecia square to oblong ; primary aperture round with a sharp sinus in the lower margin ; secondary margin forming a wide loop below, enclosing a short tubular pore (? avicularium). Be- neath the aperture is a strong prominence. Ooecium sometimes crescentic, sometimes orbicular. Not uncommon. Hastings. 51. Schizoporella discoidea. Busk. Zocecia angular, rather short, and with the front wall slightly pitted. Primary aperture has five spines and a narrow sinus; mature orifice circular and raised, but not with an angular or pointed lip as shown in Hincks' figures. Just below, and to the right or left of the aperture, there is a small round avicularium. The ooecia greatly overlap the zocecia. Rather rare. Hastings. 52. Schizoporella hyalina, Linnaeus. Encrusting seaweed. Zooecia with a satin-like gloss, ovate but tapering and curved below. The aperture is round and has a small sinus in the lower lip, beneath which there is a slight umbo. Not uncom- mon. Hastings. 53. Schizoporella venusta, Norman. Upon dead shells. Zooecia glistening, lozenge-shaped to sexagonal ; aperture sub- ovate, slightly disjunct, below which there is a prominence. From moderate to deep water ; rather rare. Hastings. 54. Mastigophora hyndmanni, Johnston. Zooecium ovate ; aperture sub-circular with a narrow sinus ; upon either side is situated a considerably modified avicularium, of which the chamber outline is often pre- served. The mandible is greatly elongated, even more so than in Microporella ciliata, and has now more the appearance of a tapering stick or whip, and is termed by Hincks a vibraculum. Encrusting an old scallop shell from deep water ; rare. Hast- ings. 12