416 REPORT ON ZOOLOGY, MDCCCXLIV. 



12 genera aquatic. Among the latter are 37 univalves dis- 

 tributed in 8 genera, and 20 bivalves (muscheln) consti- 

 tuting 4 genera. Of the terrestrial univalves, the genera 

 most remarkable for the number of species are Helix (34) 

 and Clausilia (14); of the aquatic, Limn&us (11) and PJa- 

 norbis (13); of the bivalves, Anodonta (6) and Unio (6). 



In 1844 appeared the fourth part of the Thesaurus Con- 

 chyliorum, or figures and descriptions of recent shells, edited 

 and illustrated by G. B. Sowerby, jun. A Report upon the 

 first part was given in 1843 ; with the second and third I 

 am not acquainted : they contain monographs of the genera 

 Pecten, Pteroceras, Hinmtes, Lima, and Cyclostoma ; the 

 present or fourth part gives the genera Scalaria and Cohim- 

 bella. 



Chenu ' Illustrations Couchyliologiques, ou Description et 

 Figures de toutes les Coquilles connues, vivantes et fossiles, 

 classees suivant le systeme de Lamarck, modifie d'apres les 

 progres de la science et comprenant les genres nouveaux et 

 les especes recemment decouvertes. Avec la collaboration 

 des principaux conchyliologistes de la France et de 

 1'etranger/ Of this work, brought out under such brilliant 

 auspices, 54 livraisons have already appeared up to the 

 beginning of the year 1846 ; but, it is to be regretted, 

 without the date of the year ; so that it cannot be decided 

 how many of this number belong to the year 1844. The 

 work consists of monographs, of which the livraisous that 

 have appeared contain those on the genera, Aspergillum, 

 Panopcea, by Valenciennes ; Dentalium. Siliquaria, Siyaretus, 

 by Recluz ; Solen, Clavagella, by Caillaud ; Mayihts, Stylifer, 

 Corbis, Ghjcimeris, Poronia (Cardium sp.), by Recluz ; 

 Pecten, Pedum, Unyulina, Hinnites, Galathea, Syndosmya, by 

 Recluz ; Strombus, by Duclos ; Oliva, ErviUa, Turt ; Spon- 

 dylus, Diceras, by Favre ; Laviyno, Cuv., Tridacna, Myceto- 

 poda, D'Orb, Cleidothcerus, Stutchbury (Chama albida, Lam.), 

 and Liyula, by Recluz. The term " coquilles ' ; is here em- 

 ployed in a very extensive sense ; for, besides the above- 

 named molluscous genera, the following genera of Cirripedia 



