ANNIVERSARY ADDRESS OF THE PRESIDENT. 



05 



rocks of Wales, both North and South, 110 traces of this doubtful 

 body have occurred. 



Protozoa. — Pour species of Hexactinellid sponges (by no means 

 uncommon in the Longmynd and Menevian rocks of St. David's) 

 have been described. Three of the four species belong to the Har- 

 lech beds, below the Menevian ; and all four occur in the Menevian. 

 Protospongia fenestrate Salt., is also from the Lower Lingnla-fiags 

 proper. Zittel places these sponges in the family Euretidae with the 

 Hexactinellida), and in the group Dictyonina. Mr. Carter believes 

 them to be the remains of s ar co-hex a ctinellid sponges, which Mr. 

 Sollas has confirmed *. Mr. Salter was the first to notice these Amor- 

 phozoa in the lowest and oldest rocks of Wales. The original form of 

 these sponges we know not ; it may have been flat and incrusting. 

 like Grantia. Mr. Sollas suggests that they may have been " sacci- 

 form " and anchored in the slimy ooze of the sea-bottom by a tuft of 

 anchoring-spicules f. The spicules were originally siliceous, but are 

 now converted into iron pyrites. The fact also that the spicules are 

 separate, not being " enveloped in a common coating, or united by 

 ankylosis, clearly places or assigns them to the group Lyssakina of 

 Zittel, nearly equivalent to Carter's division of the Sarco-hexacti- 

 nelfidse." The species known are Protospongia diffusa, Salt., P. fene- 

 strates, Salt., P. major, Hicks, and P. ftahellata, Hicks. No traces 

 of these have occurred either in the Harlech, Longmynd, Menevian, 

 or Lingula-flags of North Wales. They may be sought for round 

 the Harlech Dome, amidst the black shales and flags of the Menevian 

 beds. 



Annelida. — The Longmynd group yields four genera and five 

 species, Arenicolitcs uricomiensis, Call., A. sparsus, Salt., Scolites 

 socialist, Haughtonia poecila, Kin., and Histioderma hibernica, Kin. 

 If the quartzites of the Wrekin in Shropshire are of the age assigned 

 to them by Dr. Calloway, then the Arenicolites uricomiensis of that 

 author is, with the exception of Eozoon canadense, the oldest known 

 fossil. Beyond the doubtful Annelidan tracks, and one species (Are- 

 nicolites sparsus) from the Longmynd group of England and Wales, 

 we have no determined species. Two of the five species (Haughtonia 

 poecila, Kin.) and Histioderma hibernica, Kin., are Irish, from near 

 Bray Point. Nine out of ten of the so-called fucoidal or plant- 

 remains in the rocks below the Devonian are only Anneiide-burrows. 



Crustacea. — Seven genera and 14 species occur in the lowest 

 Cambrian or Harlech rocks of St. Davids, 10 of which are confined 

 to them ; the remaining 4 species (Agnostus cambrensis, Conoco- 

 ryplxe hufo, Paradoccides aurora, and P. Hicksii) connect the Har- 

 lech and Longmynd Crustacea with the Menevian. The 7 genera 

 are Agnostus, Oonocoryphe, Leperditia, Microdiscus, Paradoccides, 

 Plutonia, and Palceopyge : 2 species of Conocoryplie (C. Lyellii and 



* See Quart. Journ. Geol. Soc. vol. xxxvi. pp. 362-367, Sollas "On the 

 Structure and Affinities of the Genus Protospongia." 



t This has been confirmed through the occurrence of another form in the 

 same family, lately described by Mr. Sollas from the Silurian of Canada. 



