| To study the efficacy of symptom relief and the safety of the Dumon Y-stent for central airway obstruction in malignant main carinal involvement and in malignant tracheoesophageal fistulas. |
| The bundles contain both xylem and phloem, and are marked by the presence of large canals known as carinal canals, which also function in water conduction. |
| The basal margin on the carinal side of the spur is sometimes a little hollowed out. |
| Tergum with the carinal half of the basal margin sometimes much hollowed out. |
| The carinal internal margin of each compartment projects a little, as in the case of B. crenatus and balanoides. |
| Species are diagnosed on the basis of carinal height and the nature and number of flanking rows or parapets. |
