Starting with your organic forms with contour lines, these are mostly well done, aside from a bit of hesitation I'm noticing in the execution of your marks. Remember that executing your marks confidently, without any sort of hesitation from the moment they touch the page is important, as it helps keep our marks smooth and simple.

Overall you've approached your insect constructions quite well, but there are some issues I want to address. The biggest one doesn't actually show up that frequently in your work, but it's still worth discussing as it's not an uncommon issue. Looking here, I've pointed out how in your mantidfly drawing, you've treated the initial masses you drew as though they weren't actually solid forms upon which the rest of your construction was built. You've treated them as though they were not actually solid forms, but rather a loose plan. Constructional drawing hinges on the idea that every single addition to the construction is a solid, three dimensional form. Once one of these forms are drawn, we can't simply modify its silhouette by either cutting across it or extending it. Every change has to occur in 3D space. There are ways to actually cut into a form in three dimensions as explained here, but this isn't particularly well suited to organic subject matter. So, in cases like this, we work largely additively, which means building up new forms and defining how they relate to the underlying structure, either by defining the connection to it or establishing how this new form wraps around.

Now, this is something you've definitely done a better job at throughout much of the lesson, and honestly as you move through the lesson you demonstrate continued improvement on this front.

Another issue that stood out to me was that for this rhino beetle's head/horns, you jumped into a pretty complex form right from the get-go, and as a result, it never really felt all that solid or three dimensional. Construction forces us to work with simple forms because it ensures that each one's going to feel solid. Then we connect them to one another to build up that complexity, bit by bit, never jumping too far ahead to a point where that structure isn't supported by what's already there. Here's a demonstration of how I would build up a more complex horn, though it isn't quite the kind of horn seen here.

Lastly, don't forget that back in lesson 2 I explain that form shading will not be a part of this course, and should not be included in your drawings. It is easy to mistake the idea of "detail" with "decoration", but that is not an accurate comparison. Instead, our drawings are divided into two overall stages - construction and texture - and their goals are very similar, both being focused on the communication of visual information.

With construction, we convey to the viewer what they need to know to understand how they might manipulate this object in their hands. Through texture, we convey to them what they need to know to understand what it'd feel like to run their fingers over the object's various surfaces. It all pertains to the forms - the macro structural forms, or the micro textural ones, but it is all a matter of communicating elements that exist within 3D space. We are not simply trying to make things look good (which is what decoration is about), but rather to serve a more concrete, less subjective purpose. Always keep this in mind when approaching texture, and remember that a key part to being able to convey that information is to actually observe it and study it from your reference first.

Anyway! All in all you are making good progress, so I'll go ahead and mark this lesson as complete.