fact, all rncrusting Bryozoa ar 



valve forming a united floor, while the convex valve does not 

 cover the ventral valve, but leaves an opening more or less orna- 

 mented for the extension of the lophophore." 1 



In his first paper on the "Earlier Stages of the Terebratulina " 

 Morse had shown the same relationship between the young Brach- 

 iopod and the Pedicellina. 



The two commonest forms on our coast are the Terebratulina 

 septentrionalis, found attached to stems or shells in the seas of 

 New England, while the Lingula pyrimidata (Fig. 190, A, with the 

 peduncle perfect, retaining a portion of the sand tube ; B, showing 

 the valves in motion, the peduncle broken and a new sand case be- 



ing formed ; C, the same with the peduncle b 

 after Morse) is common in sand between tide marks, from North 

 Carolina to Florida. It is usually free, but sometimes attached. 



Development of the Brachiopods. The life-history, from the 

 time that it leaves the egg until it attains maturity, " " 



i lampshell, Terebrc 



,,<;,■. has been told by Prof. 



Before his account appeared our knowledge was ex- 

 tremely fragmentary. Morse believes that in all the Brachiopods 

 the sexes are separate. The eggs (Fig. 102, A), he says, as in the 

 Annelida, when arrived at maturity, escape from the ovaries into 

 the general cavity of the body, and are thence gathered up by 

 the segmental organs, or oviducts, and discharged into the sur- 

 rounding water. Whether they are fertilized after they leave the 



