Life Drawing Shell Number 2

This is my second attempt at accurately portraying a shell on paper.  My first shell, which is the first image, lacks line variety, contrast, all these things that I needed to improve on my second.  I feel like I accurately and proportionally created this second shell but I feel like I could have done more with it.  I tried to use darker lines to emphasize the more important parts of the shell.

The one thing I could have made a better part of my second drawing was the foreshortening.  I did that with the first drawing but I don't feel that the line variety doesn't work well with the foreshortened view.