Page:VCH Sussex 1.djvu/134

 A HISTORY OF SUSSEX are arranged in lines and arched above and below ; the front is closed in to the extent of one-fourth or one-third, leaving an aper- ture oval to sub-rectangular, with a few irregular projections around the edge. There is a raised and crenulated margin to the zooecium, and the space between this and the aperture is also crenulated in the upper part. New to Britain. From deep water; rather rare. Hastings. MlCROPORIDi€ 32. Micropora coriacla, Esper. Forming small rounded patches upon old shells. Zocecia coffin-shaped ; front wall finely perforated ; margin with a tubercle at each corner of the aperture ; aperture semi- circular. Upon Pecten opercularis from deep water ; somewhat rare. Hastings. Cribrilinid^ 33. Cribrilina radiata, Moll. Occurring in various forms, encrusting old shells. Zooecium oval, aperture semi- circular and usually armed with five spines. The front wall is radiately ribbed, the ex- tremities of the ribs often developing into blunt erect spines. Beneath the aperture there is generally more or less of a boss or umbo. Upon oyster and other shells from rather deep water ; common. Hastings. 34. Cribrilina punctata, Hassall. This species also occurs in several forms, producing patches upon old shells. The front wall is radiately punctured, and the aperture is semicircular with two spines upon the upper margin, the lower margin being thickened. In another form there are five spines to the upper margin and an avicularium at each corner. Not uncom- mon upon oyster, scallop shells, etc., from rather deep water. Hastings. 35. Cribrilina figularis, Johnston. Zooecia forming strongly marked patches upon old shells. They are ovate with sub- square apertures, the lower margin having a shallow sinus. Upon the front wall there is an inner oval area radiately punc- tured, the outer margin being plain. Avicu- laria very large. From rather deep water ; somewhat rare. Hastings. 36. Membraniporella nitida, Johnston. Zooecia oval, of crystalline brightness, forming round patches. Aperture nearly semicircular ; front wall formed of radi- ating ribs. Occurring upon Lepralia foli- acea from deep water ; rare. Hastings. 37. Membraniporella melolontha. Busk. Forming glistening, more or less foliated or branching patches upon old shells. The species resembles nitida, but there is a spine at either corner of the aperture and a plain margin around the ribbed area. Quite characteristic however is the spinous pro- cess at the bottom of this area, and very suggestive of a little tail. Upon old oyster and other shells ; rather rare. Hastings. MlCROPORELLID^ 38. Microporella ciliata, Pallas. Forming nacreous patches upon shells, weed, etc. Zooecium ovate ; aperture with five spines, sometimes six, around the upper margin, and with a raised pore beneath the lower margin. Upon one side there is usually an avicularium with a mandible of extreme length, although not as yet of the vibraculoid type. From moderately deep water; very common. Hastings. 39. Microporella malusii, Audouin. A very handsome species. Zooecia ovately lozenge-shaped ; aperture semi- circular with three spines upon the upper margin. Beneath the lower margin there is a crescentic pore, and smaller dimpled pores occur over the front wall. This species forms white patches upon old shells, stones, etc. From moderate to deep water; common. Hastings. 40. Microporella impressa, Audouin. Zooecia coffin-shaped, rather long, the lower half pointed ; aperture somewhat more deeply arched than a semicircle. Beneath it there is situated a pore, other minor ones being distributed over the front wall, more particularly around the margin. Colonies have a beautiful satin-like lustre. Upon weed from moderately deep water ; not uncommon. Hastings. 41. Microporella violacea, Johnston. Colonies rather extensive, of a violet lustre, encrusting old shells ; the zocecia are coffin-shaped, aperture semicircular to ob-ovate. In the middle of the front wall is a depression with a characteristic pore in the centre. Around the margin are radial vacancies unfilled in with shelly matter. Very common upon shells and stones from deep water. Hastings. 42. Chorizopora brongniarti, Audouin. Forming delicate pearly patches upon old shells, stones, etc. Zocecia ovate but tapering rather below, transversely wrin-