. Bulletin of the British Museum (Natural History) Zoology. Fig. 3 Pallial complex, Conulinus rutshuruensis, Thika, Kenya. Scale line 2 mm. number of new structures which themselves show a range of variation within the group, whilst the genital systems of the Arabian cerastines studied by Mordan (1986) were found to provide many useful taxonomic characters at the generic level. One external character, termed the tail crest, is also utilised as it is clearly restricted to certain genera. Table 1 lists the principal published sources of information on the anatomy of cerastines. In choosing the c
. Bulletin of the British Museum (Natural History) Zoology. Fig. 3 Pallial complex, Conulinus rutshuruensis, Thika, Kenya. Scale line 2 mm. number of new structures which themselves show a range of variation within the group, whilst the genital systems of the Arabian cerastines studied by Mordan (1986) were found to provide many useful taxonomic characters at the generic level. One external character, termed the tail crest, is also utilised as it is clearly restricted to certain genera. Table 1 lists the principal published sources of information on the anatomy of cerastines. In choosing the characters to be used in the phylogenetic analysis (Table 2), two further factors were borne in mind: all characters autapomorphic at the generic level were excluded as these cannot contribute to the structure of the tree; secondly, it was decided not to include fully correlated characters where these appeared to be functionally related to an already coded character, as this would tend artifically to increase the consistency index of the tree (Reid, 1989). Pallial Complex (Characters 1-2) The excretory system of the Cerastinae exhibits a greater degree of elaboration than any other orthurethran group. In many orthurethrans, including the Enidae, a weakly devel- oped ridge is found extending from the renal orifice along the side of the kidney to form a backwardly directed 'gutter', but in all cerastine genera a complete renal fold is developed, running the entire length of the kidney to the top of the lung cavity (Character 1). With the exception of certain small Edouardia, an additional fold runs downwards from a point of junction with the renal fold at the top of the lung, along the rectum as far as the pneumostome; this is termed the rectal fold (Character 2) and is not known from any other Orthure- thra. In the region of the pneumostome the fold flexes away from the base of the rectum and tapers to a ridge, finally fusing with the inner wall of the mantle collar (van Mol &
Size: 1155px × 2164px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollection, bookpublisherlondonbutterworths
