OF CONCHOLOGY. 125 



the septal processes are extended to the septum. There is no flat 

 top to the latter, such as is seen in Ter. dorsata, effusa and cau- 

 rina. 



This magnificent species was long confounded with W. venosa. 

 The septum and characteristic portion of the apophyses were so 

 far back that it was only by separating the valves that the peculiar 

 character of the loop could be certainly determined. It is readily 

 distinguished from W. venosa by the want of the prominent car- 

 dinal process so evident in that species, different color, the small 

 foramen, and sharply cut cardinal area. 



Laqueus suffusus, n. sp. ? Plate 7, fig. g, h, s. 



?P Terehratella rubella, Sby., Thes. v, i, p. 350, pi. 69. 



Hah. Wharf at Yokohama, Japan. R. Pumpelly. Smithso- 

 nian Cabinet, 11,784. 



Shell small, ashy white, with occasionally a tinge of salmon 

 color on the strongest lines of growth, smooth, almost polished ; 

 solid and moderately thick ; lines of growth moderately conspicu- 

 ous at intervals, but rounded and hardly interrupting the smooth- 

 ness of the shell. Punctures smaller, less widely separated, and 

 more circular, on the exterior, than in the last species ; internally 

 extremely minute. Lon., -72 in.; lat., -52 in.; diam., -SI in. 



The specific characters are best indicated by comparing it with 

 the last species, from the young of which it diff"ers in many par- 

 ticulars, morv? especially in being very much less transverse, more 

 solid, with a much narrower and longer deltidium, more arched 

 hinge line, and very much stronger and heavier hinge teeth. 



Leaving out the question of size, it diff'ers from the adult cali- 

 fornica in the following particulars : The hinge teeth are more 

 solid, and the plates which support them are usually solid masses 

 of callus, occasionally showing a projecting knob below the teeth, 

 and continuous with the remainder of the shell, instead of having 

 an indentation behind each plate. There are no excavations 

 under the hinge plate as in the last species ; the plate is narrower, 

 more excavated above and more solid. The septum falls away 

 behind the point where the septal processes are attached before 

 rising to the hinge plate. 



The point of attachment of the septum is much nearer the 

 middle of the shell than in the californica. Finally, the apo- 

 physes in this species are, proportionately, twice as solid as in 

 the last, which is ten times its size. 



Of a dozen or fifteen specimens collected by Prof. Pumpelly, 

 most had the apophyses destroyed by insects, which had eaten 

 the animal matter ; but four or five remained perfect, displaying 



