CRUSTACEANS 



and of the pretty Nephrops norwegicus (Linn.) Mr. Meek says that ' large quantities are brought 

 to Shields market by trawlers.' 1 Of shrimps the Lindisfarne catalogue names the common 

 Crangon vulgaris, which Mr. Meek also states to be fairly common in the harbour at Holy 

 Island. 8 The same writer says of the closely allied Crangon al/mani, Kinahan, that ' specimens 

 have been obtained by Dr. Brady in 20 to 40 fathoms off the Durham coast.' 3 C. nanus, 

 Kroyer, appears in Dr. Norman's Durham dredging list of 1864. The correct name of this 

 species would appear to be Philocheras bispinosm (Westwood), since Kroyer's species has been 

 successively referred to Cheraphilus and Philocheras generically, and is recognised as specifically 

 identical with the earlier Crangon bispinosus of Westwood. Dr. Norman says of Crangon 

 fasciatus, Risso, ' a single specimen of this shrimp, which had not previously been met with 

 on any part of the eastern coast, was dredged in shallow water within the Fern Islands.' 4 

 Between jEgeon fasciatus (Risso), as this species is sometimes called, and Philocheras neglectus 

 (Sars), it is now known that there is a confusing similarity of colouring, both having transverse 

 brown stripes across the fourth segment of the pleon and the tail-fan. Possibly, therefore, 

 it is the second species rather than the first that should be attributed to the Fame Islands' 

 fauna. In the Durham Dredging list for 1864 Dr. Norman includes Pandalus annulicornis, 

 Leach, and P. brevirostris, Rathke, Hippolyte varians, Leach, and H. securifrons, Norman. 

 The first of these should rather be called Panda/us montagui, Leach. It has a long rostrum, 

 attains a considerable size, and might claim to be called a prawn, if that name had any really 

 distinctive value. The second species, which Bell in ignorance of Rathke's earlier description 

 named Hippolyte thompsoni,* has been transferred by Dr. Caiman to a new genus, Panda/ina.* 

 Its rostrum is only about half the length of the carapace, and the ' wrist ' or antepenultimate 

 joint of the second leg on the right side of the animal is subdivided into only four segments, 

 not into about twenty as in P, montagui. H. securifrons, marked by a powerful and strongly 

 dentate rostrum, is now placed in the genus Spirontocaris, Bate, in which also stands the earlier 

 and perhaps identical Hippolyte spinus, Sowerby. 



The 'cloven-footed Schizopoda owe their name to a character of which they by no 

 means have a monopoly, and which needs a little explaining. Between the eyes and the 

 terminal segment of a Malacostracan there are nineteen segments, each of which potentially 

 carries a pair of appendages. Under all reserve for controversial topics, the theoretical 

 appendage may be described as seven-jointed. 7 From the first joint there is often developed 

 a branch called the epipod, and from the second a branch called the exopod. When this 

 latter is present, the remaining five joints are distinguished from it as the endopod or inner 

 branch, the first two joints being then regarded as the stem or peduncle from which the two 

 branches spring. The five pairs of legs in the Brachyura never, and in the Macrura very 

 seldom, carry exopods. In the Schizopoda, however, they are found as swimming branches 

 not only on the five pairs of legs but also on the two or sometimes all the three pairs of 

 maxillipeds that precede them. The comparative study of crustaceans shows indeed a 

 remarkable plasticity throughout the series of appendages. They readily interchange form 

 and function. The mouth-organ of one species is homologous with the claw or the walking- 

 leg of another. Antennae which in one group are fine-drawn elongated threads, in another 

 are developed into powerful spades for digging. The family of Schizopoda with which we 

 are here particularly concerned is known as the Mysidae, and is distinguished from the other 

 families, and in fact from most Malacostraca, by having no true branchiae. That they can 

 dispense with these breathing organs is probably due to the delicacy of their general structure 

 and the vivacity of their movements, so that respiration is effected through the skin. The 

 genera are very numerous. Concerning Leptomysis lingvura, Sars, Norman writes in 1892, 

 ' This species has been known to me as a member of the British fauna for the last twenty-six 

 years, at which time I took it abundantly between tide-marks at Cullercoats, Northumberland, 

 and within a year or two afterwards at Howden and Seaham Harbour on the Durham coast.' 8 

 From Seaham he also records Hemimysis lamornae (Couch) * ; Schistomysis spiritus, Norman, 

 from ' Blackball Rocks, Co. Durham, tide-marks,' 10 and S. ornata (Sars) from ' off Seaham, on 

 the Durham coast.' 11 All the four species, it should be added, are fully described as well as 

 recorded in Dr. Norman's valuable paper on the British Mysidae. Mr. Meek in 1900 



1 Loc. cit. p. 67. * Ibid., p. 67. 8 Ibid., p. 67. 



* Nat. Hist. Trans. Northumb. and Dur. i. 12. 6 Brit. Stalk-eyed Crustacea, p. 298. 



6 Ann. Nat. Hist., sen 7, iii. 37 (1899). 1 Brit. Stalk-eyed Crustacea, p. 298. 



8 Ann. Nat. Hist., ser. 6, x. 245. 8 Loc. cit., p. 249. 



10 Loc. cit., p. 255. u Loc. cit., p. 256. 



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