290 ME. W. E. COLLINGE ON THE VARIATION OF THE 



variation (fig. 7) occurred in four different specimens; twice it was paired and 

 in the other two cases present on the right side only. Here the mandibular 

 teeth appear fused (or worn down ?), whilst below these there is a large, blunt, 

 somewhat hammer-shaped process. The third variation (fi.g. 8j occurred five 

 times, twice on the left side and three times paired. It is somewhat similar 

 to the previous one (fig. 7), only the teeth are more produced and there is a 

 large blunt spine on the outer face. The fourth variation (fig. 9) occurred in 

 six specimens and paired in only one instance. There are two blunt 

 mandibular teeth and a spinous process on the outer face whose base has 

 coalesced with the lower division, forming a rounded boss. At the junction 

 of the upper and lower processes there is a small palpiform structure bearing 

 setose bristles. The fifth variation (fig. 10) was found twice, occurring once 

 on the right side and once on the left. It differs from any of the others in 

 that the upper process, which normally carries teeth, terminates in a blunt 

 process, and the lower process, which has a notched terminal portion, 

 arises from the inner instead of the outer side. The sixth variation (fig. 11) 

 occurred in two examples and on both sides of the body. Here the lateral 

 border was produced into a blunt flattened process. 



The 1st Maxillce. — Three variations were noted in these appendages (figs. 

 12-14) ; with one exception they related to the number and disposition of the 

 spines of both lobes. In one case (fig. 14) only the outer lobe varied. In the 

 first case (fig. 12) the outer lobe was wider than usual and had two large and 

 two small curved spines and three shorter blunter ones, whilst the inner lobe 

 terminated in two broad spines and two nmch shorter and smaller ones. In 

 the next case (fig. 13) the spines of the outer lobe are the same in number but 

 somewhat differently disposed, and in addition there are two short blunt spines 

 below these on the inner side. The inner lobe teiminates in a bifid manner. 

 In the third case (fig. 14) there are six curved spines on the outer lobe and 

 four shorter pointed ones. The inner lobe was normal. 



The 2nd Maxillce. — One variation only was observed (fig. 15), the external 

 distal portion being produced slightly into a tooth-like projection. 



The Maxillipedes. — Three variations were noted (figs. 16-18). Those 

 indicated in figures 16 and 17 each occurred twice, and that in fig. 18 

 three times. That shown in fig. 17 is interesting, exhibiting, as it does, 

 a peculiar flat top of the inner palp with three minute spines, quite distinct 

 from any variation noted in any other species ; moreover, I know of no 

 species of Terrestrial Isopod where the pulp of the maxillipedes terminates 

 in this manner. 



4. POECELLIO SCABER, Latr. (PL 21. figs. 19-25.) 



Eighty-eight specimens have been examined, and seven variations were 

 noted. One of these occurred four times and another twice in the mandibles, 

 three in the first maxillae, and two in the maxillipedes. 



