OF CONCHOLOGY. 171 



which, with the exception of a few places, but little is known ; 

 somewhere upon this long line of beach or rock, in some of the 

 numerous bays, it may quite likely be abundant. 



The last and most southern of the North American species, 

 a shell plentifully distributed within certain limits, is the M. bre- 

 videntatum of Wood, which is catalogued by the Adams' in their 

 Genera. Vol. I, p. 131, as " cor?iigera, Blainv.," though Wood's 

 name has, according to Prof. C. B. Adams' dates, four years 

 priority ; the more common of the synonyms by which this 

 species is known are M. ocellata, Kiener, and M. maculata, 

 Gray. 



Numerousblunders havebeen made in thehabitat of this species, 

 and it has been reported from San Francisco ! and Monterey ! 

 also from Mazatlan, all of which are erroneous, as it is undoubt- 

 edly confined to the zoological province of Panama. Carpenter 

 makes no mention of it in the Reigen collection and it is not re- 

 ported by him in the Xantus list of Cape St. Lucas shells. 



In the large quantities of material from the Gulf of Califor- 

 nia that I have overhauled and examined, I have never met with 

 a specimen of it, and I have yet to learn from any authentic 

 source of its occurrence north of San Juan del Sur Nicaragua. 



I have not attempted a systematic synonymy of the species 

 herein named ; the original works not being accessible I could 

 only quote them indirectly, and therefore the result at best 

 would have been unsatisfactory. I have, however, given a suf- 

 ficient reference to the more common synonyms, for the reader 

 to understand me, and to recognize the shells to which I have 

 had occasion to refer. 



