21 r> CAUFOUNIA ACADEMY OF SCIENCES. 



Other in middle of lower portion of wliurl: incremental lines visible; siitnn- imim^scil, dislincl; 

 aperture subovate, obliciue; outer lip thin, slightly arcuate anteriorly; inner lip smooth; posterior 

 sinus broad, very shallow; anterior sinus sliort; columella short, distinct. 



Dimensions. — Long. 12 mm.; lat. 5.5 mm.; body-whorl 7 mm.; aperture 5 mm.; deH. 

 3S degrees. 



Distiiigiiisli!il)lo fiom others of the same family by the two strong, revolving 

 ridges. Nnimnl in honor of A. M. Strong. Spocinions prononnced new .'^pooics l)y 

 l)r Dall. 



Rare in the lower San Pedro scries of San Pedro and Deadnian i.slaml; I'diind 

 also in the Pliocene of Deadinan Island, and in the upper San Pedro series at Craw- 

 fish George's. The specimen figured is the type, which is from the lower San Peilro 

 series at Deadraan Island, and is now in the United States National Mnscum. 



Plfistocene. — San Pedro (Arnold). 



Pliocene. — Santa Monica; San Pedro (Arnold). 



Subgenus Spirotropsis .SVtrs. 



Shell elongate, turreted, s])ire produced; the obtuse ape.x mamniillilorm; whorls numerous, 

 carinated in the middle; aperture narrow, oblique, with a short canal; sinus deep; remote from 

 suture. 



Pleurotoma carinata Phil, is a characteristic species. 



194. Pleurotoma (Spirotropsis) smithi, sp. nov. 

 Platk VI, Fii:. i;{. 



Shell elongate, turreted, slender; spire elevated; apex obtuse, mammillilorm ; whorls ten, 

 convex, with a .slight tendency toward angulation on the lower third of the whorl, and al)rn])tly 

 terminated at the posterior margin; suture very deeply impressed, distinct; sculpture consists simply 

 of oblique, incremental lines, which are quite deeply angulated convexly, posteriorly just a litde above 

 the middle of the w^horl; aperture narrow, oblique; outer lip thin, arcuate anteriorly; inner lip smooth 

 and incrusted; jiosterior sinus deep and remote from suture; canal narrow, slightly recurved, over 

 one-third of the aperture. 



/?/;«i?;/i/wz.f.— Long. 35 mm.; lat. 11 mm.; body-whorl 8.5 mm.; ajjerture 13 mm.; defl. 

 19 degrees. 



A long, slender species, sliglitly I'escniliiing the sinistral /'. /irrrrr^a in general 

 outline, hut easily distinguishal)ie from that species and also From all the other 

 members of this family. Some of the shells are a little more depressed than (he type. 

 Specimens identified by Dr. Dall as being a new species. 



Not uncommon in the lower San Pedro series and I'lioccne uf Ocadman 

 Island. The specimen figured is the type, which is from the Pliocene of Dcadman 

 Island, and is now in the United States National IMuseum. 



Living. — (Locality not mentioned) (Dall). 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



