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AMERICAN JOURNAL 



Order 3. Brachysiphonida. — Animal with siphons, the man- 

 tle lobes being more or less united ; siphons short, pallial 

 line simple. Families, — 



1. Chamidce, with subfamilies diamines, ffippuritidince, Tri- 

 dacnince ; 2. Lueinidce ; 3. Cardiidce ; 4. Cycladidce ; 5. 

 Cyprinidce. 



(The mantle lobes are decidedly ' less ' united in some of the 

 above ; and some have the pallial sinus.) 



Order 4. Macrosiphonida. Families, — 



1. Myadce, inch Anatinidce ; 2. Solenidce ; 3. 3Iactridce ; 4. 



Tellinidce ; 5. Veneridce. 

 ( Veneridce has short siphons.) 



Order 5. Inclusa. — Animals boring in stone, clay or wood, 

 their long imperfectly retractile siphons sometimes enclosed 

 in a shelly tube, to which the pair of shells is sometimes 

 attached ; shell incompletely covering the body, often hard 

 aud rasp-like, and with accessory pieces about the umbones. 



Families not well determined. Grastrochcenidce and Pholadidce 

 are generally recognized." 



It is scarcely worth while to criticise this arrangement at 

 length ; many things in it are curious. Thus, why have we an 

 order Inclusa substituted for Pholadacea ? and in that order, is 

 not the family Teredidce also " generally recognized," — at least 

 by those who go down to the sea in ships ? Prof. Hincks tells 

 us that his family Anodontidce is readily distinguished from 

 Unionidce by the absence of teeth ; where then will he place 

 Monoeondylcza, Margaritana, Anodonta undulata, A. edentula, 

 etc.? 



Proceedings of the Boston Society of Natural History. Sept., 1867. 



" Mr. Edward S. Morse also spoke of the success he had met 

 with in applying the principles of cephalization to the classifica- 

 tion of the- Mollusca. He drew diagrams of the six leading 

 groups of the Mollusca in their normal condition, head downward. 

 He observed that in the cuttle fish we have cephalization most 

 prominent. The head is always protruded from the sac-like 

 body, the foot is divided into numerous arms, and the jaws are 

 perfect. In the Gasteropods, or snails, the head retracts within 

 the sac, and the foot is a broad disk, by which they slowly crawl 

 about. In the bivalves, the mouth is always enclosed by the 

 mantle, and is devoid of jaws or hard parts, and the food is re- 

 ceived from the posterior end of the body, through the currents 

 of water passing in at the posterior part of the body. In the 



