118 THE NAUTILUS. 



anterior with apex pointed, posterior quite short ; ligament and 

 resilium rather short and slight. 



Long. 4/2, jilt. 3.0, diam. 3 mm. (100 : 80 : 71). 

 Long. 3.3, wit. 2.0, diam. -J.3 mm. (100 : 79 : 70). 

 Ilab.: British Columbia, apparently widely distributed and 

 common, and rather variable with respect to size and shape (no 

 doubt, also in Washington, etc.). Vicinity of Esquimalt, collected 

 by Mr. Taylor over twenty years ago, sent by Justice F. R. Latch- 

 ford, No. 63(5'2 cotypes with the lot in Mr. Latchlord's collection, 

 and lots simply marked " 13. C." at least some of them from that 

 vicinity, are in various collections ; Chill iwack Creek and Lake, 

 B. C., collected by a member of the Canada Geol. Surv. st:iflf, sent 

 by Mr. Whiteaves ; a marsh, Duncans, B. C., received from Mr. A. 

 W. llanham. The first specimens were received in 189f>, and the 

 species has been regarded as distinct ever since. 



P. fttrctttum, n. sp Mussel oblique, medium inflated, superior 



margin little curved, posterior and inferior forming one continuous 

 curve to the rounded-angular anterior end, or the posterior margin 

 slightly subtruncate ; supero-anterior slope at an angle with the 

 upper margin, well marked, straight or little curved, at an angle of 

 alt. 4.") to the longitudinal axis ; beaks slightly behind the middle, 

 rather large, rounded or slightly flattened on top; scutum and 

 seutellum slightly marked, small ; surface polished, with slight } 

 shallow stria;; color plumbeous around the beaks, straw along the 

 margins, the two shades not sharply defined, shell subtranslucent in 

 the plumbeous area, rather opaque in the light zones; hinge mod- 

 erately strong, right cardinal tooth curved with the posterior part 

 bifid, thrt outer, or posterior, shank separated by a groove even 

 above, straight or curved with the convexity below, left anterior 

 short with apex rounded, posterior oblique, slightly curved, the space 

 between them wide posteriorly ; outer lamina; of the right valve 

 small ; ligament and resilium short, moderately strong. 

 Long. 4, alt. 3.0, diam. 2.3 mm. (100 : 90 : 57). 

 Ilab.: Green Luke, Seattle, Washington, collected by Mr. P. B. 

 Randolph, with P. idiiloeiise Roper and others; types ace. No. 3896 

 b, part, of the Carnegie Museum, Pittsburgh. Probably none of the 

 specimens are full-grown. Tin 1 mussel resembles some forms of P. 

 varfab/fe Pine., but is more oblique, the color is different, and the 

 cardinal teeth are markedly different; named from the strongly bifid* 

 or bifurcate, right cardinal. 



