256 PALLOCHITON. 



fig. 10 (1784). Chiton maximus sen gigas CHEMNITZ, Conchyl. Cab. 

 viii, p. 292, t. 96, f. 819 (good), 1785. Chiton gigas GMEL., Syst. 

 Nat. xiii, p. 3206 (1788). SPENGLER, Skrivter af Naturhistorie- 

 Selskabet, iv, p. 101 (1795). WOOD, Gen. Conchol., p. 12 (1814). 

 BRUG., Encyclop. Meth., t. 161, f . 3 (copied from Chemnitz). 

 LAMARCK, An. s. Vert, vii, p. 490. BLAINVILLE, Diet. Sc. Nat. 

 xxxvi, p. 543. REEVE, Conch. Icon., f. 65. KRAUSS, Die Siidafrik. 

 Moll., p. 40, t. 3, f. 3 (young). H. & A. ADAMS, Genera Rec. Moll, 

 p. 475. SOWB., Marine Sh. of South Africa, p. 50. Chcetopleura 

 gigas SHUTTLEW., Bern. Mittheil. 1853, p. 67. Acanthopleura gigas 

 GRAY, P. Z. S. 1847, pp. 68, 169. Chiton subgigas BLAINVILLE, 

 Diet. Sc. Nat. p. 543 (young specimen). Dinoplax gigas CPR., MS. 

 Chiton albus BARBUT, The Genera Vermium of Linnaeus, Pt. 2d. 

 (London, Mar. 2, 1788), Vermes Testacea, p. 8, t. 1, f. 1 (not Oh. 

 albus Linn.) 



The dull, corroded aspect of this large species seems to be invari- 

 able in adults. The strongly raised lateral areas, black, leathery 

 girdle, and peculiar contour render it very distinct in appearance. 

 The figures of Chemnitz are most characteristic, but that it is impos- 

 sible to quote him as authority for the name must be admitted. 

 Although the bibliography of this species is rather extensive, the 

 only references worth reading are Chemnitz, Krauss and Carpenter. 



Rochebrune has cited this species from the strait of Santiago, Cape 

 Verde Archipelago (Nouv. Arch, du Mus. iv, p. 239, 1881), but his 

 paper contains such a host of erroneous locality citations that one 

 hesitates to accept any of them without confirmation. 



Genus XXII. PALLOCHITON Dall, 1882. 



Hemphillia CARPENTER MSS. 9 type H. lanuginosa Cpr. MSS. 

 Not Hemphillia Bland & Binney. Pallochiton DALL, Proc. U. S. 

 Nat. Mus. 1878, p. 29.7 (dentition described, but no generic diagnosis, 

 and founded on the undescribed species P. lanuginosus. Feb. 13, 

 1879). Pallochiton DALL, Proc. U. S. Nat. Mus. 1881, p. 283, 287 

 (Jan. 20, 1882).? Arthuria CPR. 



Valves exposed, solid, the anterior and median having sharp 

 insertion teeth slightly roughened outside ; slits of anterior valve 

 not corresponding to anything in the external sculpture ; tail valve 

 having the mucro at the posterior end, the teeth sharp and all 

 strongly directed forward ; eaves solid ; sinus notched at sides. 

 Girdle leathery, with a few deciduous hairs, but no pores. 



