288 REPORT—1843. 
have been met with in Ireland, and 5 species—Halichondria simulans, H. ega- 
gropila, H. saburrata, H. carnosa, Grantia fistulosa ; all described as new— 
being indigenous to the latter island only, make our number thirty-two. The 
most common Halichondrie thrown ashore on the north-east coast of Ireland 
are H. fucorum and H. panicea: on the Dublin coast the latter is in the 
highest perfection. H. suberea is not uncommonly dredged from deep water. 
Spongilla fluviatilis is found in several localities in the north, and both in 
swiftly-flowing and still waters. 
Grantia compressa and G. ciliata are common on Alge around the coast, 
as G. botryoides is in the north. 
Of the twenty-four British Sponges unknown as Irish, the following species 
are recorded but from one district or one locality—Geodia Zetlandica and 
Tethea cranium, Shetland Isles—Halichondria hispida, H. ramosa, H. plu- 
mosa, H. fruticosa, H. aurea, H. conus, H. rigida, H. perlevis; Spongia 
levigata and Pachymatisma Johnstonia from the south of England: of these 
ten species, seven rest on the authority of Montagu alone. Halich. aculeata 
and HA. virgultosa are from Scarborough (Mr. Bean) ; Halich. albescens and 
Halisarca Dujardinii from Berwick and its vicinity (Dr. Johnston) ; Ha- 
lich. sevosa from the Isle of Man (Mr. E. Forbes); Spongilla lacustris from 
the adjoining counties of Angus (or Forfar) and Fife; the remainder are 
Halich. palmata found in the Orkney and Shetland Islands, the east and 
south of England; Halich. Columbe, Icolmkill and Brighton; Halich. in- 
fundibulum, northern islands of Scotland and Cumbrae; Halich. coalita, 
east and south Great Britain; Halich. ficus, Scarborough and Isle of Man; 
Grantia pulverulenta, Devon and Zetland. 
Of the eight British species (or forms considered as such) of Lithophyta, 
four are known as Irish, and in the catalogue of the latter, two new species— 
Nullipora fasciculata and N. agariciformis—are included, thus making the 
number altogether six. Corallina officinalis, Jania rubens, and Nullipora 
polymorpha, are abundant round the coast. Of the four British species un- 
known as Irish, three—Corallina elongata, C. sguamata and Jania corniculata 
—have been found only in the south of England; Nullipora calcarea there, 
and also on the west coast of Scotland: this last is considered by Dr. Johu- 
ston to be merely a state of NV. polymorpha. 
Conclusion. 
The progress made in the portions of the Invertebrata of Ireland embraced 
in this Report has been indicated under the respective Classes. It is con- 
siderable in all, and exhibits, from the circumstance of our Fauna being about 
equally investigated with that of Great Britain, a fair comparison with the 
larger island*. Much still remains to be done in every department with 
reference to mere species, and to their distribution. The manner in which 
the various marine species are found associated together; the relative depths 
considered in connection with their mineralogical character; the many influ- 
ences affecting the distribution of species, are subjects of inquiry, for the study 
of which the coast of Ireland offers a rich harvestt. Accurate observations 
on the habits and geueral economy of the species are always valuable. The 
* More attention has been bestowed on the Mollusca Nudibranchia, Foraminifera 
and Annelida of Great Britain than on those of Ireland, where on the other hand the 
Mollusca Cephalopoda, Moll. Tunicata and Entozoa have (as to species) claimed more 
attention. 
+ The natural history of Ireland exclusively being alluded to, the all-important 
questions of structure and physiology are not mentioned, as they can be studied in 
every country which the species inhabits, 
