Clare Island Survey — Acarinida. 39 127 



Apart from the smaller size of the eapitnlum the present species is 

 apparently more closely allied to & tridens than to S. Hallezi. It resembles 

 the former species in size, and in the sculpturing of the dorsal and ventral 

 plates, especially of the first and second epimera. The front margin of the 

 body is very distinctly truncated, and the genito-anal plate is vase-shaped, 

 with pronounced anterior corners ; in the latter character it would appear to 

 differ from both of these species. 



In the size and shape of the eapitnlum (length 286^, breadth 138^), it 

 closely resembles S. Hallezi, but the side margins are rather distinctly angled 

 immediately in front of the basal constriction. The second palp segment is 

 armed as indicated in the preceding table, but there is also on its underside, 

 close to the apex, a stout ventrally directed process, which is not visible 

 when the animal is seen from above. 



Trouessartiella falcata (Hodge) . 



Blacksod Bay, nymph and adult in September. 



Distribution. — Littoral and abysmal regions (44), Baltic, North Sea, and 

 Atlantic, ranging into the Antarctic Ocean (to a depth of 385 metres, 45). 



Simognathus sculptus (Brady). 



Clare Island, the larva, nymph, and adult occurred commonly on 

 Lithophyllum incrustans on the shore during the month of July. The adult 

 has also been found in rock pools at Portstewart in October. 



The six-legged larval form of this remarkable species measures about 

 330^ in length, including the eapitnlum and rostrum. It has a comparatively 

 large frontal shield shaped much as in the adult, and there is a small oval 

 plate at the end of the body. Apparently the frontal plate does not alter 

 much during the development of the creature, as the plate armature of the 

 first nymphal stage (length 614^, breadth 307/i) is practically the same as in 

 the larva. 



Note. — The type specimens of the new species and varieties described in 

 this paper are preserved in the National Museum, Dublin. 



