39 126 Proceedings of the Royal Irish Academy. 



Irish coast it has occurred at Ardfry in Co. Galway, in from one to three 

 fathoms during May (Irish Fisheries Station A. 134) : and also at ilalahide 

 and Howth on the Dublin coast in February and June. 



Distribution. — Littoral region down to : J18 metres (44 1. Atlantic 

 widespread) ; Baltic. 



Sca/ptognathv.s Trouessarti sp. nov. (PI. YIII, fig. 41«, b.) 



For the single example of this interesting species 1 am indebted to 

 ilr. E. Southern, who found it amongst material dredged in from 19 to 20 

 fathoms in Dingle Bay on a bottom of fine gravel during the month of 

 August (Irish Fisheries Station W. 260). The habitat probably corresponds 

 with the very similar ground in Clew Bay (gravel and shelly sand, 24 fathoms) 

 where H. actenus, M. Southemi, H. gibbus, and H. lamellosus were found. 

 The species is undescribed, and I have much pleasure in naming it in 

 honour of Dr. Trouessart who has kindly compared my drawings of the 

 creature with his types of 8. tridens and S. Hailed. It is evidently 

 intermediate between these two species, the only hitherto known 

 representatives of this peculiar genus. 



The following characters will serve to distinguish the three species of 

 Scaptognathus. 



Size larger, total length exceeding 700 fi. 



Capituluni very large, more than half the breadth of the body ; end 

 of the second palp segment terminating on its under side in a 

 long, slender spine, 1 which is bent sharply downwards ; the 

 extremities of the two strong apical teeth are widely separated. 

 Total length of the animal 750<i . . . IS. tridens Trouess. 

 Capituluni much smaller, slightly less than half the breadth of the 

 body ; apex of the second palp segment (in dorsal view) ending 

 in a small bluntly pointed lobe, armed with a long fine hair; a 

 long setiform bristle springs from the underside of the seg- 

 ment ; both of these hairs are directed inwards ; the extremities 

 of the strong apical teeth lie almost in the same plane. 

 Total length about 716/*. . . . S. Trouessa/rti sp. nov. 

 Size smaller, total length 450/j. 



Capitulum much as in S. Trouessarti, but its sides are more evenly 

 rounded ; end of the second palp segment without a long 

 inwardly directed hair, instead of which there is a short hair 

 on its outer extremity ; ends of the two strong teeth separated. 



6'. Hallezi Trouess. 



1 Corresponding with the " apophyse olecranienne " of Dr. Trouessart's paper on this genus (92J. 



