mollusca. 
213 
Morch, O. a. L. On the systematic value of the Organs which 
have been employed as Fundamental Characters in the 
Classification of Mollusca. Ann. & Mag. Nat. Hist. xvi. 
pp. 385-396. Also in Journ. Conch, xiii. pp. 396-401. 
The lieart and the generative organs, principally the intro - 
mittent male organ, seem to the author to offer characters of the 
highest systematie value, the development of the young, on the 
contrary, to be of less systematic value than is generally believed. 
The Cejyhalopoda are said to have no more just claims to be con- 
sidered a distinct class in relation to the other Mollusca than the 
Pteropoda or the Cetacea among the Vertebrata. The classifi- 
cation of the author is the following : — ^ k z , f 
Subkingdom III. MOLLUSCA. 
Series I. Monotocardia. v. '.a A/ 
Class 1. Androgyna. .vV j '- A - 
Pulmonata : Geojjhila, Hygropliila {Auriculacea and Limnmaced). 
Tectihranchia, including the Pyramidellidm. 
Pteropoda. 
GymnohrancMa. q 
Class 2. Exophalli A. 
Tmiioylossata : A. Rostrifera, including as separate subdivisions the terres- 
trial or Cyclostomacea, the fluviatile {Melania^ Paludinay &c.), the marine 
{Ccriihmm and Turritella), differing by the metamorphosis of the young 
from the former, the parasitic ( Vennctus, Crepidida, Hipponyx, and Ca^ndus)^ 
the pelagic {Ileteropoda), and finally the Sb'omhi. B. Prohoscidifera. 
Rhnchiglossata s. Melicertigena (Rhacliiglossa^ Ilamiglossa, and Odontoglossa of 
Gray, greater part of the Canalif^res, Purpuriferes, and Columellaires of 
Lamarck). 
Toxoglossata (CanceUaria, Terehra, Clionella^ Pleurotoma^ Cmus). 
Series II. Diotocardia. ,, / 
Class 3. Pseud OPHALLIA. c > f ■ 
Rhipidoglossata, including as terrestrial subdivision the JPelicince^ as fluviatile 
the Neritince, and as marine the Trochidee and the FissurellidcB. 
Heteroglossata : Cyclobranchia— Patella jPolyplaxipho^'a— Chiton, Cirrohranchia 
—Pentalium. 
Cephalopoda. s 
Class 4. Acephala s. Dithyra. 
Pimyaria, Ucteromyaria {3fytilus), Monomyaria. 
The llccorder cannot help thinking it no great advancement 
in the natural classification to exchange the chief divisions of 
Cephalopods, Gastropods, and Bivalves for others which, being 
founded on the single character of the heart, must be artificial. 
Morch, O. a. L. On the homology of the buccal organs of 
the Mollusca. Ann. & Mag. Nat. Hist. xvi. pp. 73-79, 
with pi. vi. 
