24:2 On some Irish Sponges. 



Notes on some of the Species. 



Hamacantha johnsoni (Bowerbatik) and H. falcala 

 (Bowerbank). 



A great deal of confusion exists with regard to tiiese two 

 species. An exaniiiialion of the type-slides showed that 

 Hamacantha johnsoni possesses the following kinds of 

 spicules — oxea, diancistra of two forms, and sigmata, — while 

 Hamacantha falcula possesses styli, diancistra of three forms, 

 and toxa. The tormer species, in fact, has in recent years 

 been called Hamacantha schmidti ((Jarter) and the latter has 

 usually been referred to as Hamacaiitha johnsoni (Bower- 

 bank) . 



Rhaphidotheca marshall-halli, Kent. 



Two specimens of Rhaphidotheca are in the collection — one 

 with exotyles of the shape characteristic of R. marshall- 

 halli, Kent, and the other with exotyles shaped like those of 

 R. affinis, Carter. From an examination of the two speci- 

 mens it has been decided to regard the latter name as a 

 synonym of R. marshall-halli. The union of these two 

 species has been suggested from time to time by various 

 authors. 



(?) Clathria anchorata (Carter). 



This sponge, which is doubtfully referred to the genus 

 Clathria, was described by Carter under the name Dictyo- 

 cylindrus anchorata. 



Anchinoe Jictitius (Bowerbank) . 



The sponge called by Bowerbank Microciona Jictitia was 

 found to have the same arrangement of the skeleton and the 

 same kinds of spicules as Hymeniacidori perarmatus, Bower- 

 bank, which is the type-species of Gray's genus Anchinoe. 

 This genus may be detiued as follows : — Ectyoninte with a 

 skeleton composed of branching tibres which consist of 

 multiserially arranged smooth diactinals echinated by 

 acauthostyli. No special dermal skeleton. Microscleres 

 isochela) arcuata^ solely, or perhaps with other forms. 



P lumohalichondr ia, Carter, must be regarded as a synonym 

 of Anchinoe, Gray. 



