170 A MONOGRAPH OF THE 



nation of the species. Thus Dr. Johnston states his H. 

 sanguinea to be of "a deep blood-red colour," and Dr. 

 Grant also states that " it has always the same deep red 

 colour," while I have never found Hymeniacidon caruncula 

 of a blood-red, and never approaching that colour nearer 

 than that of a full orange tint, which in drying always 

 changes to a rich cream yellow, sometimes with a shade of 

 green. 



On measuring the length of a full-sized spiculum of the 

 sponge marked 27c, it proved to be ^rd of an inch long, 

 while a full-sized spiculum of H. caruncula, from Tenby, 

 measured rfsth of an inch in length. 



Since writing the above I have received five specimens of 

 this species from my friend the Rev. Robert Hudson, who 

 found them " under a rock at the Island of Bofin, midway 

 between Achil Head and Slyne Head, Connemara. One of 

 the specimens measured six inches long, four broad, and 

 about eight lines thick in the dried state, and one specimen 

 exceeded an inch in thickness, and in the dried condition 

 all of them were of a deep blood-red, and my friend de- 

 scribes them when alive as of " a deep scarlet colour." 



I found this species at near low-water mark at the Isles 

 of Arran, Galway, of a deep blood-red colour, with some- 

 times a superficial tint of green. 



13.Hymeniacidon mammeata, Boioerhanh. 



Sponge. Sessile, coating ; surface furnished abundantly 

 with large and prominent mammse ; minutely hispid. 

 Oscula and pores inconspicuous. Dermis stout; 

 dermal membrane pellucid, abundantly spiculous; 

 spicula acuate, slender, dispersed. Skeleton. Strong 

 and cavernous, abundantly spiculous; spicula fusiformi- 

 acuate, large, and long, and the same form small and 

 slender. External defensive spicula fusiformi-acuate, 

 short and small, very numerous. 



Colour, — Dried, nut brown. 



