134 ANNALS NEW YORE ACADEMY OF SCIENCES 



apparently interrupted by a chondrophore. The anterior teeth are few and 

 large, the posterior teeth numerous and diminishing in size toward the beak, 

 where they seem to end abruptly against the large anterior teeth. A chondro- 

 phore is almost certainly present, but. unlike the structure of living shells, it 

 seems to be situated within and below the row of cardinal teeth without ex- 

 tending to the beak and forming an interruption to them. This cannot, how- 

 ever, be positively asserted as a fact. 



Type species, Nucula ventricosa Hall. 



Limatula ? fasciculata sp. nov. 



Shell of medium size, elongate, slightly oblique. Hinge line short. Anterior 

 and posterior outlines probably nearly straight above but becoming more and 

 more strongly curved below, where they merge with the (probably) regularly 

 rounded ventral outline. The convexity is strong with a high area, so that a 

 section cut longitudinally through the two valves would be wedge shaped. On 

 the anterior side the shell descends steeply and abruptly making a rounded 

 angle with the median portion. The posterior side seems to fall away in a 

 low regular flexure. 



The surface is marked by regularly arranged costa? or groups of costa?. 

 Toward the anterior side, the costa? are single with relatively wide interspaces. 

 In the median and posterior regions, the costa? are in groups of three or some- 

 times two. having their tops about on a level, and. in this case, the dividing 

 stria? are essentially equal in width to the groups of costa?. The anterior side, 

 from the angulation to the margin, is smooth. Very likely, the costa- die out 

 toward the posterior side also. 



The area is somewhat imperfectly shown by one of the two specimens ob- 

 tained. It appears to be high and resupinate, so that the beak overhangs the 

 hinge line and it is also rather concave. It is marked by several strong, broad, 

 transverse furrows, but shows no definite pit for a resilium, though, owing to 

 the projecting state of the beak and the concavity of the area, there seems to 

 be an ill-defined hollow under the beak which is rather longitudinal than 

 transverse to the area. 



If Hind's Paleolima is a valid genus, the present species would be 

 called Paleolima fasciculata, for its characters, so far as observed, are 

 consistent with Paleolima, but if that genus is to be divided into sub- 

 genera along the same lines as the living Lima, this species would prob- 

 ably belong in a group as yet unnamed. For the present, however, I am 

 not recognizing Paleolima as distinct from Lima, so that the generic 

 designation to be used is probably Limatula, which is distinguished by 

 being smooth laterally and by having the valves not gaping. The former 

 character seems to be possessed by the L. fasciculata, but the latter can 

 not be determined, as we have only dissociated valves. The only other 

 American species referred to this subgenus is the Guadalupian form 

 Limalula striaiicostata. By a clerical error L. striaticostata was de- 



