10 Proceedings of the Royal Irish Academy. 



(3) The isochelac arcuatae have a slightly curved shaft ; they are 0-024- 

 - 033 mm. in length. The tooth is rather narrow, and is about the same 

 length as (lie alae. 



(4) Forcipes. -These are all of one kind, and, measured from the curve to 

 the end of the longer leg, they are , 038-0 , 043 mm. in length, and at the 

 most are about 0-002 mm. in thickness at the curve. The legs arc slightly 

 divergent ; one is a little longer than the other, and each terminates in a 

 small button-like knob. Sometimes the spicule is twisted so that the legs 

 cross each other. The Eorcipee are very minutely spined. Under a high 

 power of the microscope it can 1"- seen that the spines are arranged in rows, 

 aud that the points are directed towards the curve of the spicule. 



i mata are plane, and have a longer axis measuring 0T3- 



046 mm. in length. Their thickness is 0'006 mm. 



All the forms of the microscleres are present in great abundance 

 throughout the spot,. 



/' • /Vis n. sp. may be compared with the sponge assigned by 



Professor Topsent (17) to 1 Carter), which Lundbeck has 



decided is a distinct species, and to which he lias given the name Fonrpin 

 (11, Part II, p. 210). Judging from the description given by 

 Professor Topsent, the forcipes in his sponge are a different shape and size 

 from those in the new Bpecies, and, what is more important, more than one 

 kind of forceps appears to be present in the specimen from the Azores. In 

 addition, the styli of Fora metimes slightlj spined, while the 



styli of the Irish re quite Bmooth. 



The Bpiculation of 1 ry similar to that of Forcepia 



Lundbeck 11 in which Bpecies only one kind of forceps is present, 



but this spicule differs in Bhape from, as well as being longer than, the 



the new 



Grayella 



KM' 3 - : i<.ii 124, 50 miles W. "i Bolus Head, 220 fathoms. 



There are about half ting specimens of a species of 



villa growing on a piece "f /. -a. Tiny are much con- 



tracted, and their pore-1 - appear like small papilla i the 



surface of t ; 1 u spicules measure as follows :—( 1; Toruota, 



0*25-0-325 nun. in length; (2) Acanthostyli, 0*1-0*18 mm. in length; 



Uochelae arcn 19 - 0*021 mm. in length. 



The foregoing measuremeD very well with those given by Professor 



Topsent (18, p. 4' I encrusting specimens of Grayella obtained off 



the coast of Belgium, the north of I nee, and in the Gulf of Lions, which 



