242 Dr. J. D. Macdonald on the Typical Value of 
shall now attempt the grouping of all the genera which I have 
found (in many cases by repeated personal observation) refer- 
able either to Buccinidee or Muricide, substantiating my posi- 
tion by satisfactory proof and reference to the labours of others, 
furnishing decisive evidence in authentic preparations, figures, 
and descriptions. 
In order that there should be no possible mistake in the 
types of the two very distinct forms of dentition to which I 
refer, I have selected two examples for each, viz. those of 
Buccinum undatum (Pl. XVI. fig. 1, odontophore laid flat) and 
Cassidulus melongena (fig. 2) for Buccinide, and those of 
Murex tenuispina (fig. 3) and Concholepas peruviana (fig. 4) 
for Muricide. 
BUCCINIDA. 
_ Lingual dentition triserial, the distinctive feature of which 
is a stout conical fang at the inner extremity of the pleural 
plates. 
Systematic Name. References and Remarks. 
Buccinum undatum ....| Preparations and drawings, fig. 1. 
cyaneum ........ Gray’s ‘Guide to Mollusca,’ p. 22, referring 
also to Lovén, t. 5. f. 5. 
Cantharus undosus ....} Personal observation in Fiji, and an excellent 
preparation in Mr. Barron’s collection. 
Pisania striata. s:sah 5. Personal observation in the Mediterranean ; 
description, Gray, op. cit. p. 18. 
Pusiostoma mendicaria .| Personal observation and preparation. 
Cominella maculosa, & | | Figured by Hogg, op. cit. pl. 10. fig. 85; de- 
two undetermined sp. { scription, Gray, p. 16. 
Chrysodomus antiquus | Forb. & Hanl. vol. iii. p. 427, fig. 31; Gray, 
fig. 9, p.15; Mr. Barron’s preparations. 
propinquus ...... F. & H., description, vol. iii. p. 420. 
islandicus....°:..| Ibid. p. 419, pl. SS. fig. 2 ¢; Mr. Barron’s 
preparations. 
OMACMAG 5 sie vieieis & Figured by Hogg, plate 10. figs. 52 & 34, 
Nassa reticulata 
annulata ...... Description of dentition, Gray, p. 17, and 
incrassata...... Lovén’s figures, t. 5. 
arcularia ...... 
CUB ri yaw tate eh ogee Mr. Barron’s preparations. 
Neritula neritacea ....} Ditto. 
Cassidulus melongena ..| Personal observation at Jamaica, preparations 
co) y) 
and drawings. 
PACTLO sta. dis | Gray, fig. 6, p. 10, where also the dentition 
nodosus.......> of C. nodosus and of C. vespertilio is de- 
vespertilio .... | scribed. 
Triumphis distorta ....| Description, Gray, p. 15. 
