GASTROPODA (cYCLOBRANCHIA) . 
MolL 1S7 
(Dali), Shumagin Islands, syharitica (Dali), Prybiloff Islands, triangu- 
laris (Dali), Sitka to Monterey, and apicina, sp. n., Prybiloff and Aleutian 
Islands; Dali, 1. c. pp. 119-123. 
PATELLIDiK. 
Nacella p ?’osea (Dali), Aleutian and Shumagin Islands; Dali, I, c. 
p. 124. 
Lepeta cccca (Mull.), Alaska; id, 1. c. p. IIG. 
Cryptohranchia concmirica (Middend.), Alaska, var. instahilis (Dali), 
Sitka, and C. alba (Dali), Plover Bay and Aleutian Islands ; id, 1. c. 
pp. 116 & 117. 
OhITONIDJ5. 
W. H. Dall recapitulates our knowledge concerning the structure and 
development of this family, with special regard to the radula, and adopts 
the classification proposed by the late Dr. Carpenter (in MS.), as follows ; 
A. Regular Chitons. 
Lep)toidea: "^Leptochiton^ ^Hanleyia^ Deshay siella, Microplax, 
Hemiarthrum. 
Ischnoidea : *Trachydermonj ^Tonicella^ *Schizochiton, "^Chceto- 
pleiira, "^Maugerella^ Trachyradsia^ Callichiton^ Stereochiton, 
Spongiochiton, ^Ischnochit07i, ^Stenoradsia, ‘^Stenoplax, 
^Ischnoplax, *Ischno7'adsia, "^Lepidopleuriis, *Lepidoradsia, 
^Callistochiton, *Pallochiton. 
Lophyroidea : "^Chiton, *Tonicia, liadsia, Fannyia, Eudoxochiton, 
Craspedochiton. 
Acanthoidea : "^Acanthopleura, "^Lucia, ^Coj'ephiim, "*^Nuttallina, 
"*^Phacelopleura, Sclerochiton, Francisia, Dinoplax, Dawsonia, 
Beania, and Arthuria.' 
B. Irregular Chitons. 
Schizoidea : Lorica, Aulacochiton, Schizochiton, Enoplochiton, 
Onithochiton, 
Placiphoroidea \ "^Placiphora, Evplaciphora, Fremhlyia, Guil- 
dingia. 
Mopaloidea : "^Mopalia, ^Placiphorella, *Kafharina, *Acantho- 
chiton, "*^Macandrellus, Stectoplax, Notoplax. 
Cryptoidea: *Cryptoconchus, ^Amicula, ^Gryptochiton, ^Chito- 
nellus, Chlamydochiton, Choneplax, ChitoniscuSy and Crypto- 
plax. 
The radula of all genera marked with an asterisk (^) is described and 
figured. Bull. U. S. Nat. Mus. i. pp. 63-84, pis. i.-v. 
Abstract on Iheriug’s paper on the anatomy of Chiton (Morph. JB. iv. 
p, 128) in J. R. Micr. Soc. ii. pp. 404 & 405. 
Monterosato describes the Mediterranean species of Chitonidea as 
follows olivaceiis (Spengl., 1797) = squamosus (Poli) = siculus 
(Gray) = polii (Desh.) ; corallinus (Risso) = pulchellus (Phil.) ; phaseo- 
linus (Monter., 1872) ; rissoi (Payraudeau) = meneghinii (Capellini) = 
