P. pt., the palato-pterygoid bar (upper jaw bar). p.s., pre-spiracular ligament, containing a cartilaginous nodule.    From Wordnik.com.  [Text Book of Biology, Part 1: Vertebrata] Reference

Thus when the pupal cuticle is cast, they are readily broken there, and the cuticle of the midge forming beneath has a spiracular opening into the main air-trunk, ready for use during the insect's aerial life.    From Wordnik.com.  [The Life-Story of Insects] Reference

In the frog this bar of cartilage is joined directly to the otic capsule by a quadrate portion, but this is only doubtfully represented in the dog-fish by a nodule of cartilage in the pre-spiracular ligament (p.s.).    From Wordnik.com.  [Text Book of Biology, Part 1: Vertebrata] Reference

The dog-fish has ten pairs of cranial nerves, corresponding to the anterior ten of the rabbit very closely, when we allow for the modification the latter has suffered through the conversion of some part of the spiracular cleft to an eardrum, and the obliteration of the post-hyoid branchial slits.    From Wordnik.com.  [Text Book of Biology, Part 1: Vertebrata] Reference

Other structural features are the pronotal sulcus, a deep inflection visible externally, and the spiracular lobes, which form protective coverings over the first pair of spiracles (.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference