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 zocecium, and the space between this 

 and the aperture is also crenulated in the 

 upper part. New to Britain. From deep 

 water ; rather rare. Hastings. 



MICROPORID.S 



T,2. Micropora coriacia, Esper. 



Forming small rounded patches upon old 

 shells. Zooecia 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. 



CRIBRILINIDJE 



33. Cribrilina radiata, Moll. 

 Occurring in various forms, encrusting 



old shells. Zocecium 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. 

 Zorecia 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 niticla, 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. 



88 



\ 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 ci/iata, Pallas. 

 Forming nacreous patches upon shells, 



weed, etc. Zocecium 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 ma/usit, 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. 

 Zocecia 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 vialacea, Johnston. 

 Colonies rather extensive, of a violet 



lustre, encrusting old shells ; the zooecia 

 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. 



4.2. Chorizopora brongniarti, Audouin. 



Forming delicate pearly patches upon 

 old shells, stones, etc. Zooecia ovate but 

 tapering rather below, transversely wrin- 



