154 MAZATLAX BIVALVES 



suborbicular. The ligament Las a variable number of longi- 

 tudinal grooves, each broken up into portions like a necklace. 

 The shell is generally suborbicular and massive (sometimes 

 6 in. thick, Sanl.), and affords a safe asylum not only for 

 the ordinary boring and nestHng bivalves, but for numerous 

 small Gasteropods, especially Coeca, Odostomidte, VitrincUse, 

 JN^aricse, &c., which establish themselves in emptj" burrows 

 and in the galleries formed by numerous boring worms, in the 

 coloured portion of the shell. The possession of a single valve 

 therefore is quite a treasure to a patient conchologist ; as, after 

 working out the borers, he will find a plentiful supijly of species 

 among the debris. Most of the small shells described in this 

 Catalogue were thus taken from the large Chama^ and Spon- 

 dyli, by carefully passing the shell-washings through a fine 

 wire sieve, and examining the remainder under the glass. A 

 single specimen of Spondylus was found to contain the follow- 

 ing species : — Parapholas calva, G-astrochfena ovata and trim- 

 cata, Petricola robusta, EupeUaria linguafelis, Saxicava arctica, 

 Sphsenia fragilis, Cumingia 3 sp., Tellina 2 sp., Veneridse 5 sp., 

 Gouldia Pacifica and varians, Circe margarita, Cardita CaU- 

 fornica, Cardium 2 sp., Lucina, 2 sp., Kellia suborbicularis, 

 Lepton 2 sp., Mytilus 2 sp., Crenella, Septifer, Lithophagus 

 aristatus and plumula, Byssoarca gradata and solida, Chama, 

 Isognomon, Avicula, Anomia, Discina Cumingii, Bullidrc 2 sp.. 

 Chiton, Patella 2 sp., Siphonaria (2 varieties), Crepidida 2 sp., 

 FissureEa 2 sp., Hipponyx, Vermetus 2 sp., Torinia, Trochus, 

 Narica, VitrineUa 6 sp., Fossar, Littorina 2 sp., Eissoidse 5 sp., 

 Jeifreysia, Cerithiada? 5 sp., Odostomia G sp., Chemnitzia 3 sp., 

 Eulima 2 sp., Scalaria, Caecum 5 sp., Columbella 5 sp., Nassa, 

 and MargineUa 2 sp : in all 103 species, of which 7 only were 

 fragmentary. It is impossible to say how many more might 

 have been rescued from oblivion, had not the original pur- 

 chaser of the collection immediately sold off almost all the 

 lai'ge shells to the keeper of a tea garden connected with a 

 public house near Manchester, where they may be seen, the 

 Piimne built u]) into grottos, and the Spond.vli and large 

 Patella; arranged alternately round the skirting board of his 

 "Museum." These shells were carefully washed by the publi- 

 can's servant, and the precious dirt thrown away. Mr. Hanley 

 was more fortunate, and obtained many fine specimens from 

 the Havi'e Col. The largest siiccimen I obtained measures 

 long. 7', lat.7', alt.Cy'o. The measurement was however taken 

 after the shell had been decorticated to obtain the borers. 



