2(56 REV. R. B. WATSON ON THE 



smooth and shining, but not polisbed except on the muscular 

 scars, of which the anterior, semilunar in form, is pushed up 

 iuto the extreme front rounded corner of the shell, while the 

 hiuder one, also placed very high, is oval ; the two are connected 

 by a strongly marked but narrow ragged-edged pallial line, which 

 below and behind retreats into a broad, very shallow sinus. — 

 H. 0-55. B. 06. 



Mr. J. Tate Johnson, whose name I have attached to this 

 very interesting species, got the few specimens known of it 

 in a mass of oysters and corals dredged up from over 30 fatboms 

 off Funchal. On superficial examination I took it for Modiolarca 

 trapezina, Lam. ; but Mr. Edgar A. Smith kindly examined it for 

 me, and he assures me it is a Coralliophaga, and distinct from any 

 in the British Museum. The young shell scarcely shows the 

 compressed posterior and the expansion below which characterize 

 the adult. 



Fam. Teeedinidje. 

 Teredo, L. 



35. Teredo Dallii, n. sp. 



Shell small, convex, solid, translucent, glossy internally and 



externally, scored by a very slight ridge and minute furrow from 



the beak to the point of the shell, and by a fine sharp line which 



curves across the surface from the beak to the front marginal 



angle, answering to a fine raised white rib in the interior. 



Sculpture : the front area is covered with low, rounded, fine 



(sometimes, but rarely, strongish) threads, the excessively minute 



but somewhat irregular microscopic serration of which is almost 



wholly confined to the upper eilge, from which, however, it faintly 



extends to the lower side of the flat furrow above ; where these 



threads abut upon the ends of the answering mid-area ridges 



their termination is sharply defined by a small but strongly 



marked furrow, which curves down with posteriorly convex sweep 



from the beak to the apex of the right angle at the margin where 



the front area and the central area meet. On the central area 



the ridges are stronger, are nearly contiguous, and are much 



more strongly and obliquely serrated, almost tubercled. In 



number they are usually about 20 ; but even in specimens of 



equal growth the number sometimes amounts to 30. Behind this 



mid-area is a shallow flat with a slight depression, sometimes a 



