===================+=================+================================== Number | Contact (+) or | Species --------+----------+ separation (-) +---------+------------+----------- | Pairs of | of seventh pair | _ferox_ | _spinifer_ | _muticus_ Neurals | pleurals | of pleurals | (16) | (60) | (34) --------+----------+-----------------+---------+------------+----------- 7 | 7 | + | 9 (56%) | 50 (83%) | 13 (38%) 7 | 8 | + | 5 (31%) | 2 (3%) | 2 (6%) 8 | 7 | + | 2 (13%) | 3 (5%) | 3 (9%) 8 | 8 | + | | 4 (7%) | 2 (6%) 8 | 7 | - | | 1 (2%) | 14 (41%) --------+----------+-----------------+---------+------------+----------- Ventrally, the bony carapace shows ten thoracic vertebrae, the second through the ninth having well-developed, depressed ribs that are fused (no sutures) to the pleurals. The ribs of the first thoracic vertebra are represented by bony struts that extend posterolaterally and contact the anterior borders of the second pair of ribs. The two ribs of the ninth pair are free for most of their length and often are broken; they are slightly shorter than the eighth pair of ribs. The ribs of the tenth thoracic vertebra may be well-developed (KU 2219, 2666, 50856, _spinifer_, and 16528, _ferox_), but are usually broken off and represented only by transverse processes. Kyphosis