Mr. A. H. Hassall on the genus Lepralia. 407 



XLIV. — Remarks on the genus Lepralia of Dr. Johnston, 

 with Descriptions of Six undescribed species, and notices of 

 two other Zoophytes, By Arthur Hill Hassall, Esq., 

 M.R.C.S.L., Corresponding Member of the Dublin Natural 

 History Society. 



From the varied nature of the bases upon which the zoophytes 

 comprised in this genus are found, the same species being 

 sometimes met with on rocks, stones, shells and fuci, and 

 from the unyielding and calcareous structure of the majority 

 of their polypidoms, it might be supposed that the different 

 species would be subject to numerous variations, and that the 

 same species would not unfrequently present an altered ap- 

 pearance according as it was affected by either locality, age, 

 mode of drying or injury, one or all of these causes opera- 

 ting upon it at the same time, and that therefore there was 

 reason to apprehend that conditions and varieties of species 

 would sometimes be described as distinct species. From the 

 great number of species contained in this genus, to which I 

 have paid a good deal of attention, which I have examined both 

 in a recent and dried state, and from the number of specimens 

 which I have now in my possession, I think that I have the 

 means of ascertaining with tolerable accuracy the extent to 

 which the Lepralice are altered by the influences alluded to ; 

 and from the evidence now about to be detailed, it will be ap- 

 parent, I imagine, that the changes thus produced are neither 

 so numerous nor so important as might at first have been sur- 

 mised. 



First as to locality. There are specimens before me of 

 Lepralia pediostoma on granite, shale, stones, shells of va- 

 rious kinds, and on the root of Laminaria digitata and L. sac- 

 charina, its occurrence on these last being very rare ; and in 

 all these the characters of the species are well marked, and 

 do not differ in any appreciable manner from the variety of 

 the situations on which it is placed. Of Lepralia punctata 

 I have examples on the same localities as the preceding spe- 

 cies, its favourite site being however granite, and its presence 

 on fuci being even more rare than that of L. pediostoma ; of 

 Lepralia immersa and L. ciliata, on granite, shells and fuci, 

 the latter species being usually found on the roots of Lami- 

 naria digitata and L. saccharina, and of Lepralia ovalis on 

 shells and granite. Lepralia insignis* is generally met with 



* I may here record the occurrence of this species on the English coast; 

 it is probably a very widely distributed one. J have specimens of it on 

 oyster-shells from Burnham, Norfolk, and last summer I found it among 

 other zoophytes sent me by Miss Nolcken from Jersey. I have too within 



