39 112 Proceedings of the Royal Irish Academy. 



arched, with two spinous hairs ; third segment much smaller with three 

 stout bristles ; end segment short and conical with a terminal row of bristles 

 consisting of a stout, strongly pectinated hair and immediately over this a 

 row of four shorter flexed spines, which are pectinated only at their bases. 

 Palps as figured for H. hydrodromus (1, Fase. lx, n. 10) except that the 

 movable claw is more strongly bent. Berlese figures three pairs of hairs on 

 the lower face of the capitulum though he remarks : " Capitulum setis duabus 

 simplicibus auctum." In the present form there are two, strongly pectinated, 

 hairs in this position. 



Localities. — Under stones between tide-marks on the sea-shore at 

 Mulranny, Co. Mayo. On more than one occasion large colonies of adults and 

 young forms were found under stones partly embedded in mud well below 

 high-water mark. I have also observed this species running about on rocks 

 exposed by the tide at Malahide on the Dublin coast in company with other 

 littoral mites. 



Family BDELL1DAE. 

 Bdella caplllata Kramer. 



1881. Kramer 37, p. -446. 1891. Berlese 1, Fasc. lis, n. 6 (var. Berlesei 

 Tragardh). 1902. Tragardh 85, p. 17. 



Clare Island in rock-crevices between tide-marks on the sea-shore ; 

 Mweelaun [a wave-swept rock> ; Louisburgh and Westport districts. 



An interesting point concerning this species is whether the ordinary form 

 found under stones, &c, is identical with the form occurring between tide- 

 marks on the sea-shore. In his paper on the littoral species of Bdella, 

 Tragardh describes two shore-frequenting varieties of this species, i.e., var. 

 pallipes and var. pallipediformis. I have found examples of B. capillata in 

 both habitats, and cannot say that they differ in any respect, although it is 

 not unlikely that one or other of these littoral varieties may occur on the 

 Irish coast. The following is a short description of the essential characters of 

 the form here recorded; it applies equally to specimens found inland and on 

 the sea-shore. 



Length, including rostrum, from 2 to 250 mm. The measurements of the 

 last four palp segments are about 473/*, 99ju, 187/*, ilSfi. Grouped towards 

 the end of the second palp segment are five bristles, four of these are 

 arranged in pairs, the proximal half is without bristles, ventral side with only 

 one bristle, which is placed near the base ; third segment, one bristle ; fourth 

 with four bristles. In dorsal view the fifth palp segment carries about 

 twelve bristles, and there is a group of three others on its extremity ; they 



