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Vol. 36(2), 2001

Radliła

82.    Radula length: 0= long (about double than

odontophore length); 1= short (about same length as the odontophore) (thiarids, Turritella hookeri, M. modulus, cerithids, Finella dubia, Alaba incerta, Cerithidea costata, Campanile symbolicum, Serpulorbis decussatus) (CI= 20, RI= 50).

83.    Radular marginal teeth: 0= spoon shaped; 1=

hooked (Turritella hookeri, Bittium varium, Finella dubia, Alaba incerta, Campanile symbolicum, Serpulorbis decussatus) (CI= 50, RI= 80).

Several radular characters were analyzed, but thcy were almost all inconclusive or autapomorphic. Except the length, the single other radular character of interest in the studied species is the form of the marginal teeth. Most cerithioideans have the spoon-like marginal teeth, with the distal end broad and generally with cusps in its distal edge. Due to similarity with the marginal teeth of the examined outgroups (e.g., basal caenogastropods), the spoon-likeform is regarded as plesiomorphic. On the other band, sonie species have marginal teeth that are rook-like, i.e., sharp pointed distal end, with or without secondary smali cusps edging it. This type occurs in Campanile, Turritella, Serpulorbis and in the miniaturized forms Bittium, Finella and Alaba. Other comments on radula characters see Bandel (1984).

Salivary glands

84.    Site of glandular tissue: 0= only posterior to

nerve ring; 1 = anterior and posterior to nerve ring (Supplanaxis nucleus, Doryssa ipupiara, D. macapa, Pachychilus sp., M. modulus, Campanile symbolicum); 2- only anterior to nerve ring (Doryssa atrd) (CI= 40, RI= 50, additive).

The salivary glands of cerithioideans are generally typical of the basa] gastropodan grade. The glandular part stay posterior the to nerve ring, edging the esophagus. The ducts, attached to the esophagus, pass through the nerve ring and open in the dorsal wali of the buccal mass. Some species have a glandular tissue also anterior to the nerve ring, as Supplanaxis, Modulus and Campanile. But this phenomenon is very unusual among the pleurocerids, where most of glandular tissue is anterior to the nerve ring and, at least in Doryssa atra, the salivary glands are only anterior to the nerve ring (there is no branch through it) resembling slightly what happen in neogastropods. Something similar occurs in Faunus ater (cf. Houbrick, 199 lb: 47). The location of the salivary ducts opening is given in the description of each species, however, this character is very difficult to observe, generally the observation being based on extemal view by transparency. Maybe detailed histological examination may change the detail.

85.    Site in haemocoel: 0= around esophagus; 1 =

extending posterior by haemocoel (Doryssa ipupiara, D. atra, Batillaria minima) (CI= 33, RI= 0).

Buccal mass

86.    Folds in dorsal wali of buccal mass: 0= a pair;

1= two pairs (Melanoides tuberculatus, Supplanaxis nucleus, Doryssa atra) (CI= 33, Rl= 0).

87.    Buccal ganglia site: 0= near median linę; 1 =

lateral (thiarids, Supplanaxis nucleus, pleurocerids, cerithids, Finella dubia, Alaba incerta, Batillaria minima, Cerithidea costata) (CI= 100, RI= 100).

The site of the pair of buccal ganglia in outgroups and in some cerithioideans, is on the dorsal wali of the buccal mass, near the median linę. Although, in most examined cerithioideans, the buccal ganglia have lateral, sometimes very close to insertion of m2; with a long connective uniting both. This condition is regarded as apomorphic based on comparisons with State of the outgroups. In thiarids, the buccal ganglia are pigmented and very large.

Esophagus

88.    Inner surface: 0= two pouches; 1= one pouch

(pleurocerids); 2= several narrow longitudi-nal folds (thiarids); 3= few (2-4) broad lon-gitudinal folds (Bittium varium, Finella dubia, Cerithidea costata)', 4= transversal folds (Alaba incerta)', 5= smooth (Serpulorbis decussatus) (CI= 71, RI= 77, not additive).