Carter

The Carter Ink Company had been around since 1857, but it wasn't until the 1920s that the company made a brief foray into producing writing instruments for use with its inks.  In 1925, Carter bought the DeWitt-LaFrance Company, which was making metal pens and pencils and had only just started to make pencils in hard rubber; Carter picked up from there and quickly expanded into celluloid.   All the pencils shown accept standard .046" leads.

​The company first began producing pens and pencil in the mid-1920s.  The earliest models tended to look like Eversharps, and the company made both all metal and hard rubber versions.  The clips, patented by DeWitt-LaFrance and used on Carter pencils from the outset, make them easy to spot.
The black hard rubber example has the original price sticker.  Compare it to the Signet.

Around 1925 or 1926, the company started using some spectacular colors  (they called it "Coraltex") on high quality, rear drive pencils. 
The quality was there, but they didn't hold up very well over time.  Tops tended to come off, the ball on the clip is easily broken off, and the nose cones seem overly prone to denting.

In 1929, the company started using different patterns and colors of celluloid, which the company referred to as "Pearltex", and by 1931, the company's offerings were more streamlined.  The ringtops at left were sold with matching pens in a celluloid case.  As seen in the pictures, the durability issues remained a problem.
The two examples on the right are the latest in the group.  They are standard middle-joint twist pencils.  On the black and pearl model, the name "Carters" on the clip can only be seen under magnification. 

In the closing days of the company's production of pens and pencils, around 1932 or 1933, the pencils wer redesigned.  Gone are the original DeWitt-La France clips, replaced with a more conventional press clip.  These are also middle joint pencils with the same mechanism used on the Parker Parkette line (since Cross supplied Parker mechanisms at the time, it's safe to assume Cross also supplied Carter.  
The plastics used on later Carters were unique.  The middle example is not black, but a very dark brown with bronze veins running through it.