138 Proceedings of the Royal Physical Society. 
rectangular or more or less trapeziform, longer than broad, scarcely curved in 
front, with anterior margin very finely serrulate, the whole of its integument 
distinctly roughened with lines of punctures. Sternum with punctured integu- 
ment, and further, on each side with four distinct little areas picked out with 
lines of punctures; truncate behind almost in a straight line. Anal shield 
subcircular, small, furnished behind the anus with a rather long spiniform bristle. 
Legs provided with short subspiniform bristles. 
Coleoptrate nymph almost like the female but more villose and without any 
genital shield, with body more elongated, acute behind, distinctly shouldered, in 
colour less deeply tawny. Chel stronger than those of the female. 
Male up to 750 p in length; 480 » in breadth. 
Female up to 800 » in length ; 530 in breadth. 
Coleoptrate nymph up to 720 » in length; 420 p in breadth. 
Habitat.—On the sea-shore under seaweed ; quite frequent in France, Spain 
(and in Britain‘). 
Famity BDELLIDA (Snourep Mires). 
Two species occur commonly on the shore at Millport. One of these, 
Molgus littoralis (L.), was recorded by King and Russell (1909) in a paper 
read before this Society, and specimens were then exhibited The other 
appears to be della longicornis (L. 1758), Sig Thor, 1902. The reason for 
the double authority given is that Linnzeus seems to have applied the same 
name to two different species, the one in his Systema Nature (1758), the 
other in his Fauna Suecica. 
Molgus littoralis (L.). 
= Acarus littoralis, L., Systema Nature, 1758. 
= Bdella basteri, Johnston, Acarides of Berwickshire, Trans. Berwickshire 
Naturalists’ Field Club, vol. ii. (1847), p, 221. 
= B. marina, Packard, Amer, Naturalist, 1884. 
= B. littoralis (L.), I. Tragardh, 1902 ; ete. 
This is a large scarlet mite found running over stones or amongst dry 
and decayed seaweed, for the most part above high-water mark, but at low 
water travelling down into the tidal region amongst the drying stones. 
It is, according to Sig Thor (1902), the largest species of Bdellid known, 
reaching a length of from 2°5 to 3°5 mm. 
None of the Millport specimens so far examined exceeded 2°5 mm. 
Its characteristic features are the presence of several bristles on the 
mandible (Fig. 8, Mpp.), and the cylindrical form of the fifth joint of the 
palp (Pup. 5) which ends in a number of bristles of almost equal size. 
Triigardh (1902), in summing up what is known of the habits of littoral 
1 Mr Win. Evans, F'.R.S.E., has taken this species in the Forth Area since 1906, 
