WordPress Gallery displaying uls instead of dl

I’m having a problem with the wordpress gallery and any help would be greatly appreciated.

My wordpress gallery is displaying ul’s instead of dl’s and it is displaying all thumbnails vertically in a single column.

This is the code it is outputting:

<article id="post-15" class="post-15 page type-page status-publish hentry clearfix" role="article">

					<header>

						<h3>Gallery</h3>

					</header> <!-- end article header -->

					<section class="post_content">

						<ul class="block-grid four-up">
							<li><a href='https://bofinangling.com/gallery/gang/' title='gang'><img width="150" height="150" src="https://bofinangling.com/wp-content/uploads/2012/10/gang-150x150.jpg" class="attachment-thumbnail" alt="gang" title="gang" /></a></li>
							<li><a href='https://bofinangling.com/gallery/fish/' title='fish'><img width="150" height="150" src="https://bofinangling.com/wp-content/uploads/2012/10/fish-150x150.jpg" class="attachment-thumbnail" alt="fish" title="fish" /></a></li>
							<li><a href='https://bofinangling.com/gallery/sea-angling/' title='sea-angling'><img width="150" height="150" src="https://bofinangling.com/wp-content/uploads/2012/10/sea-angling-150x150.jpg" class="attachment-thumbnail" alt="sea-angling" title="sea-angling" /></a></li>
							<li><a href='https://bofinangling.com/gallery/tester/' title='tester'><img width="150" height="150" src="https://bofinangling.com/wp-content/uploads/2012/10/tester-150x150.png" class="attachment-thumbnail" alt="tester" title="tester" /></a></li>
						</ul>

					</section> <!-- end article section -->

					<footer>

						<p class="clearfix"></p>

					</footer> <!-- end article footer -->

				</article> <!-- end article -->