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Show 1882.] ' L I G H T N I N G ' A N D ' P O R C U P I N E ' E X P E D I T I O N S . 667 that there is a real affinity between Chiton and Patella, and that Chiton does not materially differ from other mollusks. Mr. Dall also regards the Chitons and Limpets as closely allied. See his exhaustive and valuable remarks on the morphology and classification of the Chitons in the ' Scientific Results of the Exploration of Alaska' (1879), in which he proposed no fewer than 33 genera distributed into 9 groups. Dr. Mcintosh has noticed that Chitons scoop out sandstone like Limpets. Specimens occurred on the coast of Bohuslan, in 12 fathoms, on the leaves of Laminaria saccharina. 2. CHITON DISCREPANS, Brown. C. discrepans, Brown, 111. Conch, p. 65, pl. xxi. f. 20: B. C. iii. p. 214; v. p. 198, pl.lv. f. 4. 'Porcupine' Exp. 1870: Atl. St. Gibraltar B., with C. fascicularis. Distribution. Norway and Sweden (Loven)1, Cornwall and Channel Isles to Mogador, Mediterranean and Adriatic; 0-25 fms. Fossil. Pliocene ; S. Italy. Post-tertiary : Selsea. There are a few obsolete synonyms. B. Acanthopleura, Guilding. Girdle spinous, without tufts. 3. C H I T O N MENDICARIUS, Mighels. C. mendicarius, Migh. Boston Journ. Nat. Hist. 1841, i. p. 49 ; 1842, iv. p. 42, pl. 4. f. 8. C. Hanleyi, B. C. iii. p. 215 ; v. p. 198, pl. Iv. f. 5. ' Porcupine ' Exp. 1869 : St. 2, 65. 1870 : Atl. 24 (plate only). Distribution. Loffoden and Faroe I. to South Devon, Mediterranean (Monterosato), Caribbean Sea (Petit), eastern coasts of North America ; 8-300 fms. Fossil. Post-tertiary: Norway. C. Nagelfar of Loven and C. abyssorum of M . Sars appear to be this species of unusually large size. The late Mr. Barlee dredged in Shetland a specimen an inch long. M y Piedmontese shell which I named C. Hanleyi turned out to be the young of C. caietanus. C. striyillatus of S. Wood, a Coralline-Crag shell, is more probably C. apiculatus of Say, which is also a North-American species ; but the fossil is only known from disjointed plates. The "Crag" Mollusca include many North-American species. The inside of each plate in the middle is strengthened by a thick bow-shaped rib. C. Lepidopleurus, Leach. Girdle irregularly granular. 4. CHITON CAIETANUS, Poli. C. caietanus, Poli, Test. utr. Sic. i. p. 10, t. iv. f. 1,2. 'Porcupine' Exp. 1870: Med. Algesiras B. (young). |