80 



Y.I. KANTOR, A. MEDINSKAYA AND J.D. TAYLOR 

 n S- re btsi 



Fig. 27 Antiguraleus morganus (Barnard, 1958). Semidiagrammatic longitudinal section of the foregut (salivary glands not to scale). 



Fig. 28 Radulae of Crassispirinae. a, Antiguraleus morganus b, Paraguraleus costatus. Scale bars = 20um. 



Buccal mass and oesophagus 



The long, buccal mass lies posterior to the proboscis, and is equiva- 

 lent to nearly half of the proboscis length, with thick walls and a 

 rather broad inner cavity, which is not curved. There are large 

 extensible buccal lips. The oesophagus is not elongated between 

 buccal mass and nerve ring, which is situated closely posterior to the 

 buccal mass. A buccal sac is absent. 



Glands 



The salivary glands are large, paired, and consist of single, coiled 

 tubes but with the acinous morphology. The venom gland does not 

 change histology after passing anteriorly through the nerve ring. It 

 opens at the border between the buccal mass and oesophagus just in 

 front of the nerve ring. The muscular bulb is small, the wall formed 



of two equal layers of longitudinal fibres, divided by a connective 

 tissue layer, with an innermost very thin layer of circular muscle. 



Odontophore and radula 



The odontophore is medium-sized, with a pair of unfused cartilages 

 formed of one layer of cells. The radula consists of marginal teeth of 

 the wishbone type (Fig. 28a). The major limb of the tooth is elongate 

 with a pointed tip and a constricted waist in the middle of the tooth. 

 Below this constriction, the lower marginal edge of the tooth is 

 extended as a 'soft' buttress to attach to the radular membrane. The 

 minor element is slender and shorter, attached to the distal blade of 

 the major element and broadens slightly at the base, where it 

 attaches to the membrane. The marginal teeth are long, ca. 120pm 

 (1.2%ofSL, 3.2% AL). 



