A HISTORY OF DEVONSHIRE 



Sub-Class MALACOSTRACA {continued) Sub-Class MALACOSTRACA {continued) 



Order Brachyura {continued) Order Brachyura {continued) 



Division Brachyura genuina {continued) Division Brachyura genuina {continued) 



Tribe Oxyrrhyncha (carapace anteriorly narrowed, Tribe Oxystomata (having the oral frame narrowed 

 often forming a 'sharp beak') {continued) anteriorly) {continued) 



Family Mamaiidae Family Lzvcosudae {continued) 



Mamaia sqmnado (Herbst). Cancer squinado, Heihst; Ebalia tumefacta (Montagu). Cancer tumefactus,Mon- 

 Maia s.. Leach, Bell ; Mamaia i., Stebbing ' tagu ; Ebalia Bryerii, Leach, Bell 



— cranchii, Leach. Cranch's Ebalia (Bell) 



Tribe Oxystomata (having the oral frame narrowed 



anteriorly) Division Brachyura anomala or Dromiacea 



Family Leucoshdae Family Dromiidae 



Ebalia tuberosa (Pennant). Cancer tuberosus, Pen- ? Dromia vulgaris, Milne-Edwards. A conjectural 

 nant ; Ebalia Pennantii, Leach, Bell member of the Devon fauna 



It appears that at least a dozen of the species above enumerated were introduced to science by 

 Montagu and Leach. On these it is fitting that some remarks should be offered. But there are 

 others on which our Devonshire authorities have thrown illuminating gleams. The species Xantho 

 hydrophilus and X. poressa are nearly allied. Bell explains that in the former the fingers of the cheli- 

 peds are brown and the movable finger is grooved above, whereas in the latter the fingers are black, 

 without grooves, Parfitt, however, describes a link between the two, a female specimen of 

 X. poressa, in which ' the movable finger is grooved above, having a line of punctures in the 

 centre of the groove.' This might perchance have been a hybrid. The Italian naturalist, O. G. 

 Costa, discussing X. poressa in the Fauna del Regno di Napoli, is sarcastic on the making of species 

 out of simple varieties, which he thinks might be almost indefinitely multiplied. Leach founded 

 the genus Pilumnus in 1815. He found the species P. hirtellus extremely abundant all along the 

 rocky shores from Plymouth to Berry Head, and noted that sometimes the left, at others the right 

 cheliped is the larger, besides which, he says, ' the wrists and hands are sometimes quite smooth, 

 without the slightest appearance of that granulated surface which Linn6 considered as the essential 

 mark of this species.' ^ Portunus pusillus, when established by Leach in 18 15, was attributed first 

 of all to the waters of Devon, only with appended acknowledgement of another locality. In the 

 ■ following year he writes: 'This beautiful little species is found occasionally in the Firth of Forth ; 

 and is very common in some parts of the southern coast of Devon, where it is taken by dredging in 

 deep water. The fingers are generally annulated with red, and whitish, and the back is not 

 unfrequently ornamented with a red streak or spot.' ^ Portunus emarginatus. Leach, is another 

 truly Devonian species, having been first ' discovered at Torcross.' The author might well say, 

 * it is extremely rare,' since, except the original specimen which he received from Mr. Gibbs and 

 deposited in the British Museum and that noted as rare by Cocks at Falmouth in 1 849, no other 

 appears to be on record. Its emarginate ' front ' may be merely an occasional variation. To the 

 name founded upon this feature Leach unluckily gave what is called page precedence over his 

 better named Portunus arcuatus. The latter designation must therefore lapse as a synonym. 

 The species P. holsatus, Fabricius, and P. marmoreus. Leach, though reckoned as independent 

 members of our fauna by good authorities, are doubtfully distinct. Of the latter Leach writes : 

 ' This elegant species, which derives its name from its colour, was discovered by G. Montagu, 

 Esq. It is very common on the sandy shores of southern Devon, from Torcross to the mouth of 

 the river Exe, and is frequently found entangled in the shore-nets of the fishermen, or thrown on 

 the shore after storms. It is distinguished from every other discovered species by the rounded 

 dentations of the front, the very slight elevation of the lines on the hands, and by the convexity, 

 remarkable smoothness, and marbled appearance of the shell.'* It must, however, be remem- 

 bered that Leach does not notice P. holsatus, except indirectly by the description of a faded speci- 

 men, which he called P. lividus. With regard also to the extreme smoothness of P. marmoreus, it 

 may be noticed thf'^O. G. Costa calls P. holsatus in Italian Portuno rasato, the crab all shaven and 

 shorn. * 



Portumnus latipes (Pennant) is discussed by Leach, Bell, and Parfitt under the later name given 

 it by lycach, who writes : ' Portumnus variegatus is one of the most beautiful, as it is the most 



' ^outh African Crust. (1905), pt. iii, p. zz. 



' MakcostracaPodophthalmata Britanniae, text to pi. xii (i March, 1816). 



' Op. cit. text to pi. ix (i Sept. 1816). * Encycl. Brit. (ed. 5), supplement, p. 411 (1816). 



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