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A HISTORY OF CORNWALL generic definition regards the claws as imperfectly chelate, while in U. deltaura, which in Bell's opinion may be the female of U. ste//ata, Bell represents this imperfection as vanishing. A similar vagueness prevails in species of the next genus. On A xius stirynchus, Leach, the following comment is made by Couch : ' The male of what I judge to be the same species differs from the female, in the snout, which in my specimen of the latter was finely notched, and without the well-marked longitudinal ridge of the former. The outer antennae of the male are furnished with a ridge of firm hair on their inward line, decreasing towards the point, which the female is without, and the former also has well-marked brushes near the lateral edges of the abdominal rings. This species, like those of the genus Callianassa, has the habit of burrowing in the sand, from which it rarely emerges ; and then it seeks shelter in a crevice covered with weeds, for it is sluggish in its motions, and if distant from a soft bottom in which to sink, incapable of escaping an enemy. A female, that I obtained loaded with spawn, was dug out of the sand in the middle of summer.' 1 Of this species Cocks says : ' Perfect specimens rare. Arms, heads, and mutilated bodies in the stomach of the Gadus aeglefinus, Trigla lyra, Trigla hirundo, etc. : not uncommon, Helford and Pendower Sands, low-water mark : very rare.' In 1856, R. Q. Couch contrasts the specific characters of A. stirynchus with those of a supposed new species, in which the raised margin of the rostrum is ' festooned or lobulated,' the hand is unarmed on every part instead of having a row of spines on its outer surface, the movable finger is deeply furrowed externally instead of being smooth, the telson is quadrangular instead of elongate-triangular, and the first pleon-segment has on its front margin two projections which pass forward and join the margin of the carapace. 2 But A. M. Norman subsequently decided that this unnamed species was really A. stirynchus? R. Q. Couch indeed appears to be distinguishing his specimen not from the type but from inadequate or inaccurate descriptions of the type. In these rare sand-burrowing crustaceans the following differences are easy to observe. The Callianassa has its first legs chelate and almost extravagantly unequal in size, and the second legs also chelate, but symmetrical with very small chelae. The Axius, which Couch calls the ' Slow shrimp,' likewise has the first and second legs fully chelate, but the first pair are not strikingly unequal. In Upogebia the second legs are simple, and the first, at least in U. stel/ata, have the fixed finger so much smaller than the movable one that they do not together form a complete chela. Bell is at variance with Leach in attributing a difference in this respect to the doubtful U. deltaura, but there are exotic species in which the chela is fully developed, and these are sometimes transferred on that account to a separate genus or sub-genus Gebiopsis* The title of ' Burying shrimp ' which Couch applies to the Callianassa would equally well suit all these burrowers. It does not appear that like ' burying beetles ' they entomb alien bodies, but only that they excavate tunnels in the sand for the purposes of their own life. The tribe Scyllaridea is divided into two families sharply distinguished by the second antennae, which are short and laminar in the Scyllaridae, but long and subcylindrical in the Palinuridae. To the former no doubt Borlase is referring when he says : ' That fine shrimp, Squilla lata Rondeletii (lib. 1 8, chap. 6), rubra, alba maculata, I found on Careg Killas in Mount's Bay.' * Under Scyllarus arctus (Linn.), ' The Broad lobster,' Adam White says, ' Pennant records this as having been found by Dr. Borlase on Careg Killas, in Mount's Bay, Cornwall, and a specimen, procured in Cornwall in 1856, was sent to Sir Wm. Jardine, Bart.' 6 Under the same designation Mr. G. B. Sowerby in his continuation of Leach, 7 remarks : ' The name of this curious crustacean was first added to our list of British fauna by Dr. Bor- lase, who found specimens in Mount's Bay, Cornwall. They have also been not unfrequently taken on other parts of our coasts. The more usual order in decapodous Crustacea is reversed in this case, the first pair of legs being single-clawed, and the last weakly double-clawed.' Spence Bate in 1878 sums up the account given by the British Association Committee in 1867 as follows : 'Several specimens of this very interesting animal have been taken of late, one of which was at Polperro, and Mr. Couch had the honour of announcing its first addition to the British fauna. Since then it has been taken by Mr. Cornish at Penzance, and at Plymouth near the entrance of the Sound. Two of these were pregnant with spawn. Two also were taken in the stomach of a cod-fish. Those that I have seen were about four inches long. The zoea of Scyllarus, according to Anton Dhorn [Dohrn], are Phyllosoma.' 8 It is probable that all our authorities are referring to the same species now known as Arctus ursus, Dana, which differs in many respects from the vastly larger Scyllarus latus (Rondelet), as determined by Latreille. If Couch and Borlase refer to the same species, Bate must be wrong in saying that Couch had the honour of announcing its first addition to the British fauna, and, whether the specific name ought to be arctus or ursus, Sowerby cannot be right in saying that the name was 1 Fauna, p. 77. ' The Zoologist (1856), vol. xiv, p. 5282. 3 Ann. Nat. Hist. (1868), ser. 4, vol. ii, p. 177. 4 For a full discussion of this point, see Marine Investigations of South Africa (1900), S.A. Crustacea, p. 42. 5 The Nat. Hist. ofCormv. p. 274. 6 Pop. Hist. Brit. Crustacea, p. 9 1 . 7 Mai. Pod. Brit. (1875), text to Plate XXXIV. " ' Revision,' p. 30. 268