PLATE 127. 



CcELOGEAPHIDA. 



Diam. Page 



Fig. 1. Cceloplegma murrayanum, n. sp., . . . x 40 1757 



One valve of the bivalred shell, seen from the inside, of the usual ovate 

 form. 



Fig. 2. Cceloplegma murrayanum, n. sp., . . . x 40 1757 



One valve of the bivalved shell, seen from the inside, of the rarer poly- 

 hedral form, which may be distinguished as a different species 

 (Cceloplegma tritonis, compare p. 1758). h, hemispherical inner 

 valve ; g, galea ; s, its base. 



Fig. 3. Cceloplegma murrayanum, n. sp., . . . x 40 1757 



The entire shell, seen from the base or the aboral pole (dorsal and ventral 

 valve connected by delicate teeth, catching into one another). 



Fig. 4. Cceloplegma murrayanum, n. sp., . . . x 100 1757 



h, The two hemispherical inner valves of the shell, seen from the right 

 side ; n, the central nucleus inside the central capsule ; d, the astro- 

 pyle ; g, the galea ; t, the nasal tube, arising from its base ; m, its 

 mouth; p, the phaeodium, which is partly thrown out by the nasal 

 openings, filling up the galea and nasal tube. 



Fig. 5. Cceloplegma murrayanum, n. sp., . . . . x 200 1757 



h, The two hemispherical inner valves of the shell and the enclosed 

 central capsule, seen from the oral side ; d, the radiate operculum 

 of the astropyle, seen in the frontal fissure between the two valves ; 

 n, the nucleus ; k, the crystals ; g, galea ; g^g 5 , the styles arising 

 from the galea ; t, nasal tube ; m, mouth of it. 



Fig. 6. Cceloplegma murrayanum, n. sp., . . . . x 600 1757 



Oral part of a central capsule, in profile, o, Opening of the proboscis ; 

 d, radiate operculum of the astropyle, which gives rise to the pro- 

 boscis ; e, the outer, ?', the inner membrane of the capsule ; k, 

 groups of crystals ; n, nucleus. 



Fig. 7. Cceloplegma murrayanum, n. sp., . . . . x 1000 1757 



Three single groups of crystals, taken from the central capsule. 

 Fig. 8. Cceloplegma murrayanum, n. sp., . . . . x 300 1757 



One inner valve of the shell, in profile, h, hemispherical valve ; 

 g, galea ; g l -g b , the tubes arising from it ; t, rhinocanna or nasal 

 tube ; in, its mouth ; b, frenulum. 



Fig. 9. Cceloplegma murrayanum, n. sp., . . . . x 400 1757 



g, The galea ; t, rhinocanna of one inner valve ; m, its mouth ; p, phceo- 

 della filling up both galea and rhinocanna ; b, the sagittal frenulum 

 connecting the galea and the mouth of the rhinocanna. g l -g b , 

 the styles arising from the galea; s, sieve-plate, which separates 

 the cavity of the galea from the hemispherical valve (h). View in 

 profile. 



Fig. 10. Cceloplegma murrayanum, n. sp., . . . x 300 1757 



An anchor-pencil of the outer shell. 

 Fig. 11. Cceloplegma murrayanum, n. sp., . . . . xlOOO 1757 



A single anchor-thread of a pencil. 

 Fig. 12. Cceloplegma murrayanum, n. sp., . . . x 300 1757 



Terminal branches of a style. 

 Fig. 13. Cceloplegma murrayanum, n. sp., . . . x 1000 1757 



A single terminal branch of a style. 



