REPORT ON THE BRACHYURA. 
55 
Pisa ( Arctopsis ) tribulus (Linne). 1 
? Cancer tribulus, Linne, Syst. Nat., ed. 12, p. 1045, 1766. 
,, longirostris, Herbst, Naturg. Krabben and Krebse, i. p. 230, pi. xvi. fig. 92, 1782; var. 
nec, Eabricius. 
1 Arctopsis lanata, Lamarck, Syst. Anim. sans Vert., p. 155, 1801. 
? Maia rostrata, Bose, Hist. Nat. Crust., vol. i. p. 255, 1802; var. 
„ armata, Latreille, Hist. Nat. Crust., vol. vi. p. 98, 1803; var. 
Cancer biaculeatus, Montagu, Trans. Linn. Soc. Lond., vol. xi. p. 2, pi. i. fig. 2, 1815. 
Pisa gibbsii, Leach, Trana Linn. Soc., vol. xi. p. 327, 1815; Malacostraca Podophthalmata 
Britanniae, pi. xix. figs. 1-4. 
,, „ Milne Edwards, Hist. Nat. Crust., vol. i. p. 307, 1834. 
,, „ Bell, Brit. Crust., p. 27, 1853. 
„ ,, Heller, Crust, siidlich. Europa, p. 41, 1863. 
„ „ Brandt, Bull. Acad. Sci. Petersb., vol. xxvi. p. 410, 1880. 
,, nodipes, Leach, Zool. Miscell., vol. ii. p. 50, pi. lxxviii., 1815. 
„ „ Brandt, tom. cit., p. 412, 1880. 
Inachus musivus, Otto, Nova Acta Acad. Caes. Leop. Carol, p. 334, pi. xx. figs. 2, 3, 1828. 
Pisa armata , Milne Edwards, Hist. Nat. Crust., vol. i. p. 308, 1834 ; Atlas des Crust, in Cuvier, 
Regne Animal, ed. 3, pi. xxviii. fig. 1. 
,, „ Heller, Crust, siidlich. Europa, p. 43, 1863; var. 
„ „ Brandt, Bull. Acad. Sci. Petersb., vol. xxvi. p. 410, fig., 1880. 
Tenerife, 78 fathoms (a small male) ; off Fayal, 50 to 90 fathoms (a male). 
The larger (but still small) male from Fayal measures as follows ; — 
Adult . Lines. 
Length of carapace and rostrum, . . . . . 10i 
Breadth of carapace, ....... 5 
Millims. 
22-5 
10-5 1 
Hyastenus, White. 
Hyastenus, White, Proc. Zool. Soc. Lond., p. 56, 1847. 
„ Miers, Journ. Linn. Soc. Lond. (Zool.), vol. xvi. p. 658, 1879, and synonyma. 
Carapace subpyriform, rounded behind, moderately convex, smooth, tuberculated or 
spinose on the dorsal surface. Prseocular spine small or obsolete, spines of rostrum long 
1 1 am in great uncertainty as to the proper designation (both generic and specific) of this common species. Linnaeus’ 
description of Cancer tribulus well applies to it except as regards the legs, which are described as filiform, and except that 
he mentions two (not one) posterior tubercles on the carapace. Arctopsis lanata of Lamarck has been referred to this 
form by A. White, and Lamarck’s generic name has priority over the almost universally used Pisa of Leach, but 
Lamarck’s description is so brief, vague, and obviously incorrect, that I do not think myself justified in using his name 
in preference to one about which there is no uncertainty, and which has been generally adopted. It may, however, as 
noted above, perhaps be used for a subgeneric designation. 
Pisa armata (Latreille) is, I think, a mere variety. The distinctive characters attributed by Milne Edwards to this 
form are, however, much better marked in a specimen in the British Museum collection than in Milne Edward’s figure 
in the Atlas of the Regne Animal and Hist. Nat. des Crustaces. 
