ON MOLLUSCA OF THE WEST COAST OP NORTH AMERICA. 529 



Fig. 



2. Penitella xilopliaga, Val. [may be the adult of fig. 4], 



3. Penitel a tubigera, Val. [may possibly be intended for Ph. penita], 



4. Pholas rostrata, Val. [is probably Netastoma Danvinii, Sby. jun.l. 



5. Ungulina htticola,V&\. [may be an extremely bad Petricola robusta], 

 '6. Corbula luticola, Val. [is probably S2)h(Bnia fragilis]. 



7. Bornia luticola, Val. \KeUia Laperoussii]. 

 l. [=& 



8. Saxicava clava, Val. [=& legumen, Desh., = S,pholadis, var.]. 

 The identification of these species is attended with great uncertainty, as 

 the types have not been seen, and the artist appears to have studied effect 

 rather than accuracy. 



42. Voyage of Sulphur. The types of these species appear to have been 

 scattered. Only a part are now to be found in the very valuable collection 

 of Admiral Sir E. Belcher, in which most of the shells are, unfortunately, 

 destitute both of names and of locality-marks. 



Murex Belcheri [belongs to Purpuridse, and may be considered the type of 

 the genus Chorus]. 



Ranella California. [After comparing a series with the Cumingian speci- 

 mens of R. ventricosa, it appears that the diagnostic characters are not con- 

 stant.] 



Marginella sapotilla. [The type in Mus. Cuming is much smaller than 

 the ordinary condition of M. prunum=ccerulescens, Lam., to which species 

 the common Panama shells were referred by Mr. Cuming. In his collection, 

 however, they stand thus : Ordinary Panamic type " sapotilla, Hds. : 5-13 

 fms., sandy mud, Panama, H.C" Another tablet of the true Panama shells 

 " Marginella, n. sp., Panama," " San Domingo" having been crossed ouf. 

 The small West Indian form, analogous to the typical sapotilla, is given as 

 " glans, Mke." The large West Indian shells, with violet tinge behind the 

 labrum, are " ccerulescens, Lam., Panama," without authority. Another series 

 of the W. Indian type is given as " ccerulescens, var., Lam., 10 fms., sandy 

 mud, Panama," without authority. Either habitat- errors have crept into the 

 Cumingian labels, or else Mr. Redpath's observation will not hold, viz. that 

 the Atlantic shells have a posteri< r pinch on the labrum, which is not seen 

 in the Pacific. All the authentic series examined irom the two coasts bear 

 out his view. There will be two opinions as to whether this be more than 

 a mere local distinction.] 



Solarium quadriceps. [On comparing suites of S. granulosum from the 

 Texan coast with series from the Gulf of California, it appeared that on each 

 side of the Peninsula the shells went through similar changes in strength of 

 sculpture, size of umbilicus, number of spiral granules, &e. ; nor could any 

 clue be obtained by which the coasts could be separated in a mixed collection. 

 Hinds's shell stands at the furthest extreme of -removal from S. granulatum.~\ 



43. U. S. Exploring Expedition. The shells of this collection were depo- 

 fiited in the Patent Office in Washington, D.C., where, notwithstanding the 

 great care of Mr. Varden, the curator, they were not a little tampered- with. 

 Dr. Gould laboured under great difficulties in his work of description ; he 

 had access only to that part of the collection which happened to be unpacked 

 and exposed to view during the brief period that his professional engagements 

 allowed of his visiting the capital ; and his request to be allowed to take 

 doubtful shells to Europe for identification was refused. The materials also 

 were of an unsatisfactory kind, a large proportion of the specimens being 

 much weathered, and many of the locality-marks being manifestly erroneous. 

 ,lf occasional errors have been detected in his great work, they may fairly be 

 let down to causes over which the author had no control. Many of these 



1863. 15 



