SCAPHOPODA. 



Fam. 23. Teredinidae. The branchiae are to a large extent contained in 

 the branchial siphon. Siphonal region vermiform, provided behind with two 

 accessory shell-pieces. Shell very small, covering only anterior part of animal. 

 Teredo L. , T. navalis L. (Fig. 271), shipworm, was the cause of the famous- 

 dam-break in Holland at the beginning of last century. 



Sub-order 7. ANATINACEA. 



Hermaphrodite ; ovary and testis with separate orifices ; external gill directed 

 dorsally, and without the reflected (outer) lamella. 



Fam. 24. Pandoridae. Foot tongue - shaped, without 

 byssus. Siphons very short. Pandora Bruguiere ; Myo- 

 chaina Stutchbuiy. 



Fam. 25. Lyonsiidae. Foot cylindrical, byssiferous ; 

 siphons short. Lyonsia Sturton ; Lyonslella Sars. 



Fam. 26. Anatinidae. Foot slender, without byssws ; 

 siphons long; a fourth pallial orifice. Aimtina Lam.; 

 T/iracia Blainville ; Pholadomi/a Sowerby. 



Fam 27. Clavagellidae. Foot reduced, without byssus ; 

 siphons long, united ; valves continued by a calcareous 

 tube secreted by the siphons. Clavayella Lam. ; Asper- 

 g ilium Lam. (Fig. 272). 



Order 5. SEPTIBRANCHIATA. 



With branchial septum. 



There are three pallial fusions, two siphons more or 

 less elongated, and two adductors. The gills (Fig. 264 D) 

 have the form of a muscular septum, extending from the 

 anterior adductor to the junction of the two siphons and 



surrounding the foot, with which it is continuous. This Flc " 2 ' 2 - She11 of 

 , . , ... Aspergillum javanum 



septum presents symmetrical orifices. (after AI-ims) 



Fam. 1. Poromyidae. Siphons short ; foot elongated. 



On each half of the septum there are several groups of lamellae separated by 

 orifices. Palps well developed. Hermaphrodite. Poromya Forbes ; Silenia 

 Smith. 



Fam. 2. Cuspidariidae. Siphons elongated, united ; foot reduced ; palps 

 reduced or absent; branchial septum pierced by isolated symmetrical orifices; 

 sexes separate. Cuspidaria Nardo. 



The genus Entovalva Voeltzkow, is not well enough known for its affinities to b^ 

 determined. The mantle has a posterior orifice ; the foot is large, with a posterior 

 sucker. There is an hermaphrodite gland. It inhabits the oesophagus of a 

 Holothurian from Madagascar. 



Class II. SCAPHOPODA* (SOLENOCONCHAE). 



Dioecious Mollusca ivithout eyes or heart. The edges of the mantle 

 are fused to form a tube which is open before and behind, and secretes 

 a tubular calcareous shell. 



* Lacaze Duthiers, " Histoire de 1'organisation et du developpement du 

 Dentale," Ann. Sc. Nat. 1856-58. Plate, " Ueb. d. Ban u. d. Verwandt. d. 

 Solenoconchen," Zool. Jahrb. f. Morph. Bd. 5, 1892. Kowalewsky, "Etudes sur 

 1'Embryogenie du Dentale," Ann. du Mm. de Marseille, t. 1, 1883. 



