47 136 Proceedings of the Royal Irish Academy. 



Arenicola ecaudata Johnston. 



1909. Arenicola ecaudata. Ashworth, p. 2. 1912. A.e. Ashworth, p. 132. 



Post-larval stages of this species were frequently obtained in Laminaria 



roots in Blacksod Bay, in September, and young stages in March. Adults 



were rare in Blacksod Bay, only 4 specimens being found, whilst .4. branchialis 



was common. 



Habitat. — Blacksod Bay — Adults on 2 occasions, under stones on the 

 shore. Post-larval stages frequently in Laminaria roots. 

 Clew Bay— Shore of Clare Island. Ballynakill Harbour — 

 Under stones on the shore. 

 Distribution. — British Isles; Scandinavia; France. 



Arenicola branchialis Audouin and Edwards. 



1909. Arenicola Gritbii. Ashworth, p. 2. 



1912. A. branchialis. Ashworth, p. 138. 



The only post-larval specimens of this species known up to the present 

 were found in Laminaria roots in Blacksod Bay, in September, 1910. Young 

 specimens were found in March. Adults were common in Blacksod Bay, 

 living in gravel and coarse sand under stones. They were not found in clean 

 sand, but live in numbers in the sand of Zostera beds. Some of the specimens 

 are coloured a dark greenish brown ; others are light brown with broad bands 

 of a deeper colour. 



Habitat. — Blacksod Bay — Found on the shore on 10 occasions. 

 Ballynakill Harbour — Three specimens on the shore. 



Distribution. — West shores of the British Isles ; France ; Spain ; 

 Portugal ; Morocco ; northern Mediterranean ; Black Sea. 



Family SCALIBREGMIDAE. 

 Scalibregma inflatum Eathke. 



1901. Scalibregma inflatum. Ashworth, p. 237. 



This species was found on many occasions. It is fond of muddy places, 

 and lives also between flakes of schist, in the sand of Zostera beds, in muddy 

 gravel, and in coarse shelly sand. 



A large number of small specimens were taken in the surface tow-net at 

 night, in Ballynakill Harbour, in the months of March, April, and May. 



Habitat. — Blacksod Bay — Found on the shore on 3 occasions. Clew 

 Bay — Dredged in Inishlyre Hbr., in 4 fms., on a bottom of 

 mud. Dredged in 12 fms., off Killary Hbr., on a bottom of 

 sandy mud. Ballynakill Harbour — Taken on 6 occasions 

 in the surface tow-net at night. 



