CRUSTACEANS 



lobes which form a pseudo-rostral projection. Diastyloides biplicata^ Sars, has the telson 

 strongly bent in the male, and in both sexes two oblique pleats or ridges sculpturing the broad 

 carapace. Leptostylh ampuUacea (Lilljeborg) has the uropods, that is, the appendages of the 

 penultimate segment, very slender, but the front part of the body at least in the female 

 swollen out. This genus is a sort of connecting link between the Diastylida; and Lam- 

 propidas, since here as in the latter family the third and fourth legs of the female have 

 rudimentary exopods. While, however, the males of Diastylidae have two pairs of pleopods, 

 those of the Lampropidas have either three pairs or none. Hemilamprops rosea (Norman) 

 has the ' eye very large and conspicuous, with beautiful red pigment and 8 corneal lenses.'* 

 The family name refers to the brightness of the eye, but, as in the preceding family, the 

 presence of an effective eye is not one of the essential characters. For Pseudocuma cercaria 

 (van Beneden) the name P. longicorne (Bate) should be adopted as the earlier, though this 

 specific name is not particularly appropriate, since it refers to the long second antennas which 

 are found only in the male, and which are found in that sex of other species. No females 

 among the Sympoda have these antennas elongate. P. simi/is, Sars, preferably called P. simile, 

 is a larger and less slender species than the preceding, reaching a fifth of an inch in length or 

 rather more, instead of barely a sixth. 



The remaining species of this list agree in having no distinct telson. The Bodotriidae 

 have five pairs of pleopods in the male, and exopods only on the first pair of legs in both 

 sexes. To this family belongs Bodotria scorpioides. The Leuconids have the negative 

 distinction of being, so far as is known, always devoid of eyes. They have exopods on the 

 first four pairs of legs in the male, and on the first three pairs in the female, and pleopods on 

 the first two pleon-segments in the male. Leucon nasica (not nasicus) has an upturned pseudo- 

 rostral projection. In choosing the specific name, no doubt the classically-minded Kroyer 

 inferred that some ancestor of the virtuous Roman, Publius Scipio Nasica, must have had the 

 end of his nose directed heavenward at a similar angle. In Eudorella truncatula. Bate, 

 belonging to the same family, there is also upturning of the pseudo-rostral lobes, but it is 

 carried out in such a way that the medio-dorsal line of the carapace is continuous with the 

 margin of the lobes, showing no nasal prominence. Such is the case also in Eudorellopsis 

 deformis (Kroyer), with the distinction that here each lobe uplifts a little horn-like process 

 breaking the evenness of the dorsal line. The Campylaspida agree with the preceding 

 family in having exopods on the first four pairs of legs in the male, but differ by having 

 them on only the first two pairs in the female, and by having no pleopods in the male, a 

 deficiency which is shared by the females in all the Sympoda. In Cainp\laspis the great 

 swollen carapace is, especially in the gentler sex, in marked contrast with the slender pleon. 

 C. rubicunda (Lilljeborg) was named from its bright red colouring, whereas the little C. glabra, 

 Sars, is whitish. Finally, the Nannastacida are a family in which all the known species have 

 eyes, in contradistinction to the Leuconidas in which none have them, and to the other 

 families in all of which some species are seeing, and some sightless. In Nannasiacus the 

 eyes are paired. But in Cumella they are confluent, as is customary in this group of animals. 

 C. pygmaa, Sars, justifies its name by being only about a tenth of an inch long, even so 

 however not being absolutely the smallest of the Sympoda that has been described. 



The Isopoda, so named on the supposition that all their legs were very much alike and 

 pretty nearly equal, come under popular notice chiefly as 'rock-slaters' and 'wood-lice.' 

 They are strongly distinguished from all crustaceans hitherto noticed in this ciiapter, by the 

 respiratory apparatus. Instead of being sheltered under the carapace and attached to 

 appendages of the head and trunk, in the genuine isopods it is developed in the appendages 

 of the pleon. There is, however, a detachment of anomalous isopods, which some autiiorities 

 would place in a quite separate division, because their breathing arrangements are in fact in 

 the cephalothorax, and their eyes when present, though not stalked, are on well-defined 

 lobes of the head. Of this set Dr. Brady records Lcptognathia longireinis (Lilljeborg) from 

 '5-6 miles off Souter Point, 30 fathoms,' and from 'a depth of 4 fathoms off Scaton 

 Carew.'* The uropods arc relatively long, but the whole animal is less than a sixth of an 

 inch in the female, and less than an eiglitii in the male, altliough 'this is the largest and 

 finest of the Norwegian species' of Leptognnthia.^ 



Several of the normal Isopoda arc mentioned by Bate and Westwood as occurring on 

 the Durham coast. Thus, they say of :Ega hicarinata, Leach, in the family jEgid.-c, that 



' Loc. cit., p. 22. * Naf. Hilt. Trans. Northumb., etc., xiv. (i), 95. 



* San, Crustacea of Norway, ii. 27. 



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