TRANSACTIONS OF THE SECTIONS. 91 



On the Scope of Conchological Inquiries. By Dr. Morch. 



1. The three continents, viz., 1. Europe and Africa ; 2. North and South America ; 

 3. Asia and Australia, owe their configuration to a definite plan, which can be traced 

 in very old geological periods. 



2. These continents represent three different formations, geologically speaking. 



3. The old world is inhabited by the higher forms of each natural division, 

 whilst the lower are found in the new world; e. g. the Quadrumana of the old 

 world are higher in organization than those of the new world. The lowest mam- 

 malia are characteristic of Australia. 



4. America is an island in the Atlantic Ocean, being in zoological respects limited 

 by the abyss between the Gallopagos and Sandwich Islands. 



5. The limits of marine fauna? depend chiefly on climate. 



6. Most species of one fauna have some characters in common, e. g. colour, sculp- 

 ture, &c* 



7. Each fauna contains analogous species. 



8. The lingual dentition is of the. greatest importance in deciding whether the 

 specific differences of univalve shells have arisen from external influences, such as 

 saltness or depth of water, or originally existed. 



On the Classificatiom of the MoUusca. By Dr. Morch. 



1. The primary divisions of subkingdoms among animals cannot be founded on 

 the locomotive organs, as proved in the case of Pinnipedia and Cetacea among 

 Vertebrata. 



2. Lungs and gills indicate only relative superiority and inferiority, but not the 

 limits of systematic divisions. 



3. The presence of respiratory organs depends only on the thickness of the skin 

 or other protective coverings impermeable by oxygen. 



4. The development of gills is dependent on the extent of the area impermeable 

 by oxygen. 



5. The form and size of the renal organ correspond with those of the gills. 



6. According to the number of the auricles of the heart, the Mollusca are divided 

 into two groups,Monotocardia and Diotocardia, analogous toThermalia and Sicremia 

 among Vertebrata. The former division has a copulatorj' organ, which is wanting 

 in the latter. 



7. Gasteropoda with a retractile male organ are androgynous. 



8. Gasteropoda with an external but not retractile male organ are bisexual, with 

 the exception perhaps of Valvata, according to Moquin Tandon. 



9. The development of a male organ indicates relative superiority of the nervous 

 system. 



10. Great fertility indicates want of intelligence to provide for offspring. 



On the Zoological Affinities of the Mollusca. By Dr. Morch. 



1. Kadiata, in the sense of Cuvier, cannot be considered a natural division, bein°- 

 founded only on external form. 



2. The Acalepha3 have, in respect of external form, the same relation to the 

 Acephala as the Cephalopoda to Gasteropoda ; and they have, in respect of the 

 gastro-vascular system, the same relation to Acephala as the Phlebenterata to Gas- 

 teropoda. 



3. The division of Entozoa is artificial like that of the Infusoria, being founded 

 only on characters dependent on their habits. 



4. The Platyhelmia have the same relation to Pellibranchiata as Linguatulfe to 

 the Acari. 



5. The locomotion of the Pellibranchiata is performed by the hind part of the 

 mantle, the true foot being rudimentary only. 



* Cf. Malacozoologische Blatter, 1859. 



