1882.] 'lightning' AND 'porcupine' EXPEDITIONS. 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 iu 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. 



y 2. Chiton discrepans. Brown. 



C discrepans. Brown, 111. Conch, p. 65, pi. xxi. f. 20 : B. C. iii. 

 p. 214; V. p. 198, pl.lv. f. 4. 



'Porcupine' Exp. 1870: Atl. St. Gibraltar B., with C. fas- 

 cicular is. 



Distribution. Norway and Sweden (Loven)!, Cornwall and Channel 

 Isles to Mogador, Mediterranean and Adriatic ; 0-25 fms. 



Ibssil. Pliocene ; S. Italy. Post-tertiary : Selsea. 



There are a few obsolete synonyms. 



B. Acanthopleura, Guilding. 

 Girdle spinous, without tufts, 

 l^ 3. Chiton mendicarius, Mighels. 



C. 7nendicarius, Migh. Boston Journ. Nat. Hist. 1841, i, p. 49 : 

 1842, iv. p. 42, pi. 4. f. 8. 



C. Hanleiji, B. C. iii. p. 215 ; v. p. 198, pi. Iv. f. 5. 



' Porcupine ' Exp. 1869 : St. 2, 65. 1870 : Atl. 24 (plate only). 



Distribution. Loffoden and Faroe I. to South Devon, Mediter- 

 ranean (Alonterosato), Caribbean Sea (Petit), eastern coasts of 

 North America ; 8-30(1 tms. 



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. My Piedmontese shell which I 

 named C. Hanleyi turned out to be the young of C. caietanus. 

 C. strigillatus of S. Wood, a Coralhne-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" 

 MoUusca 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). 



