CRUSTACEANS 



tor the report of this interesting addition to our fauna, I hazarded the 

 prophecy that we should find the species also in England. It so hap- 

 pened that early in the following June I had occasion to visit Matlock 

 Bridge with my wife. A couple of days after our arrival we set ourselves 

 to seek out such localities as were likely to harbour terrestrial Isopoda. 

 We had scarcely been engaged five minutes in the first favourable spot 

 when Mrs. T. R. R. Stebbing exclaimed that she seemed to have found 

 something new. This was really the case, and though, as subsequent 

 researches showed, the specimens were not very numerous, they justified 

 my venturesome prediction by proving to be the veritable Armadillidium 

 pulchellum of Brandt, as described by Budde-Lund in 1885. It should 

 however be mentioned that the latter author ascribes the honour of 

 having first named this pretty little species not to Brandt but to Zencker. 

 It is further worth noting that, though A. vulgare is usually black and 

 uniform in colouring, there are sometimes found specimens brightly 

 mottled with three or even four rows of yellow spots along the back. 

 It is therefore desirable to reproduce in part Budde-Lund's description of 

 the species A . pulchellum^ which is not only new to England but as yet 

 peculiar therein to this county. The length is a fifth of an inch, with 

 a breadth of about half the length. It is thus much smaller than the 

 other English members of the same genus. In regard to shape and 

 texture it is oblong oval, very convex, smooth, shining, minutely but 

 not very densely punctate. The outer antenna? are equal to three- 

 sevenths of the length of the body, and the flagellum has its first joint 

 one-third as long as the second. This last is an important character, 

 because in A. vulgare there is much less difference and in the other two 

 British species little or none in the length of these two joints. In the 

 first segment following the head the lateral margin just in front of its 

 hinder angle is obliquely sub-truncate. The terminal segment of the 

 pleon is broader than long, sub-semicircular. The colour is brown with 

 the margins and four rows of spots yellow or beautifully red. The 

 seventh segment of the trunk is almost entirely black. 1 In the figure 

 which accompanies Dr. Scharff's paper this last character does not 

 appear, nor is it mentioned in his notes on the colouring. In the 

 Derbyshire specimens the seventh segment has the light spots sometimes 

 pretty strongly developed, but in every case flanked on either side by a 

 dark patch. Thereby this segment is in rather a marked manner dis- 

 tinguished from the preceding segments which have the lateral parts of 

 the dorsal surface light-coloured. 



Of the Amphipoda little is yet known from Derbyshire. These 

 sessile-eyed Malacostraca are commonly regarded as a companion group 

 to the Isopoda. They have the body similarly divided, the middle part 

 being composed of seven distinct leg-bearing segments. But whereas 

 in the Isopoda the appendages of the abdomen have some parts modi- 

 fied for the respiratory function, in the Amphipoda this purpose is served 

 by branchial sacs attached to several of the trunk-legs. In this respect 



1 Budde-Lund, Isopoda Terrestria (1885), p. 70. 

 107 



