loitk Descriptions of new Species. 411 



nize species, and very little subject to even a slight vari- 

 ation, except from injury. Out of all my specimens I have 

 only noticed one, of Lepralia punctata, in m hich the apertures 

 of the cells present an appearance somewhat different from that 

 by which it is usually characterized ; in it the anterior wall 

 of the cell is plain, and not continued up into the apertures — 

 notwithstanding* this the specimen is easily identihed. 



The polypes of the Lepralice resemble very closely those of 

 the Flustne ; they are mostly of a pinkish colour ; in one ex- 

 ample oi Lepralia pediostonia which I examined, and which 

 may probably be regarded as the type of the genus, I re- 

 peatedly counted seventeen tentacula to each polype ; but it is 

 likely that I was deceived, and that the number really is either 

 sixteen or eighteen, for there would appear to be a dislike to 

 odd numericals in the Ascidian type of zoophytes. 



On making a careful examination a short time since of a 

 number of specimens of Irish zoophytes collected by me 

 during the winter of 1840 and spring of 1841, and which 

 had previously received but a partial and hasty investigation, 

 I was gratified by the discovery of the follov/ing undescribed 

 species belonging to the genus Lepralia, dravrings of which 

 will be shortly prepared and sent to Dr. Johnston for his 2nd 

 edition of the ' British Zoophytes,' a work which, from the 

 great progress which zoophytology has made within the last 

 year or two, will doubtless be replete with interest, and the 

 early publication of which is much to be desired. 



Lepralia semilunaris. 



Spec. Char. Crust when dry opake white ; form of cells 

 not very distinct ; walls usually perforated ; apertures semi- 

 lunar, mostly furnished with an operculum ; a single pointed 

 tooth arises from the anterior wall of each cell about its centre. 



Two or three specimens of the above Avell-marked species 

 have occurred to me on old valves of Pecten maximns, trawled 

 up off Bray, near Dublin ; it is therefore most probably a deep- 

 water species. Its distribution is not confined to Ireland, as 

 I have since met with a single specimen on oyster-shells from 

 Burnham, Norfolk. In some cells the anterior tooth is broken 

 off, leaving an aperture in its place ; there is also sometimes 

 an appearance of two spines, one on either side the aperture, 

 produced by the incomplete removal of the operculum. 



Lepralia auriculatd. 

 Spec. Char. Crust generally reddish even when dried, 



spreading circularly ; cells but little raised, and their form ill 

 defined; apertures pitcher-shaped, small, looking ujjwards 

 (the spout-like prolongation being very prominent), and armed 



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