14 FOSSILS FROM STRAITS OF MAGELLAN WHITE. 



The species is a large one, the largest fragment in the eollectiou hav- 

 ing a transverse diameter of not less than 3 inches ; but it is a smaller 

 one which is figured on PI. ii. All the fragments in the collection seem 

 to be portions of the living chamber, none of them showing the septa 

 or sutures of the same. 



CONCHIFERA. 



Geaus Lucina Brnguire. 



Lucina ? to-wnsendi sp. nov. 



[Plate III, Figs. 1 ami 2 ] 



' Shell large, much inflated when adult, for a spcicies of Lucinaj um- 

 bones moderately prominent ; beaks almost terminal; lunule small but 

 somewhat deep; the postero-dorsal portion of each valve laterally com- 

 pressed and defined from the body of the shell by a deep, long, narrow 

 groove which meets its fellow at the postero dorsal extremity of the 

 shell. Surface marked by strong lines of growth. In its robust form 

 and the somewhat ])romineut umbones this shell does not agree with 

 •typical forms of Lucina, and furthermore its hinge is not known. Its 

 affinity with the Lucinoids, however, is suggested by the distinct dorso- 

 urabonal grooves, its distinct lunule, its depressed ligament, and its 

 marginal outline. The figures on Plate iii are of natural size. 



The specific name is given in honor of Mr. Charles H. Townsend, 

 who collected the fossils described in this article. 



Plate IL 



Hamites elatior? 



Fig. 1. Lateral view of a fragment of the living chamber. 



Fig. 2. Outline of trausverse section of the same. It is probable that the natural 

 t>afcline was more nearly circnlar. as the specimen from which it was drawn has been 

 somewhat compressed. 



Plate III. 



Lucina f iownsendi. 



Fig. 1. Lateral view of an adult example. 

 JFiG. 2. Dorsal view of the same. 



