66 MB. S. HANLET ON THE LINNEAN MS. OF THE ' MUSEUM ULRICiE. 



Lister (without numerals!) was referred to in illustration; the early 

 unimproved account of the beaks and ligamental area ran as follows : 

 " Umbones distantes, oblique incurvati. Rima hians striata transversim 

 ad angulos acutos " : " et profunde immersis " was an addition. 



A. GRANOSA. A. subcordata, sulcis muricatis, rima obtusangule striata, 

 utrinque angulura formante. 



The name was evidently borrowed from RumTph\\is,v,'hose Pecten granosus 

 (" 143. t. 44. f. K.") was referred to in the manuscript, though neither 

 quoted in the printed copy nor in the 'Systema' (ed. x.). "Bonan. 2. 

 n. 73," and Lister (without numerals) were also cited. 



A. DECUSSATA. A. leuticularis, dccussatim substriata, apicibus reflcxis. 



For a detailed account of this shell, to which no specific name was 

 attached in the MS., the ' Museum Ulricas ' was referred to, previous to its 

 publication. 



A. FALLENS. A. lenticulari-subobliqua, decussatim striata, rima brevi. 



This was the type referred to in the ' Systema.' 



A. PECTUNCULUS. A. Icuticularis sulcata, decussatim rugosa. 



" Arg. t. 27. f. B," and Lister without numerals appended, were the 

 unpublished synonyms. The expressions " leviter," " exteriore tenui ; 

 sulcata," " in arcum," were not parts of the original copy, which con- 

 tained, however, the unprinted paragraph " latere interiore margine pro- 

 minente notato." There was no specific name attached to either this or 

 the next species. 



A. GLYCiMERis. A. Icutiformis, transversim substriata, rima laevi. 



The ' Chama glycimeris Bellonii ' of Lister (t. 247) was an unprinted 

 synonym. 



The following suppressed description of an unnamed Ark that was allied 

 to, if it were not, fusca or barbafa, was found in the manuscript. The 

 ' Museum ' had been referred to in the synonymy of the latter in the ' Sys- 

 tema,' but the species was not mentioned in the published version. 



Area ovalis, corapressiuscula, apicibus subcontiguis. 



Testa rudis, ferrugineo-fusca, longitudinaliter striata, striis quasi ex 

 punctis callosis concatenatis, alternis striis majoribus ovatis, parum obliqua, 

 minus lateribus gibba, rotunda absque angulis. Margo aequalis, edentulus. 

 Apices recurvi fere tangunt se invicem. Rima dentibus minutissimis, antice 

 longius extensa, nee recta. 



OSTREA. 



The ver} natural genus Pecten was separated from the unsymmetrical 

 oysters, with the following definition : — 



PECTEN. Testa subrotunda, altera planior, basis transversa, anguli 

 transversi (auriculae) ad basin. Cardo cavitas conica, striis utrinque 3 lon- 

 gitudinalibus obliquis. 



The genus OSTREUM, enlarged by the addition of the true oysters 

 confounded with the Mytili, the Meleagrince, Avicula, and the Anomia 

 placenta, was thus characterized : — 



