No. 434] NOTES AND LITERATURE. 



"3 



in the Inarticulata, has often been a subject of remark. Prof. Morse 

 succeeded in transporting live specimens of Lingula from Japan to 

 this country. " One cannot help," he says, " associating this remark- 

 able vitality of these genera with their persistence through geological 

 horizons from the Cambrian to the present day almost unchanged in 

 character." The freedom and extent of movement of the valves of 

 Lingula, in locomotion and in burrowing, are quite at variance with 

 Hancock's notion of the operation of the muscles, and much more in 

 accord with what one would be led to expect from the general con- 

 formation of the valves. The action of the setae of the anterior 

 mantle margins of Lingula, in forming tubes for the passage of incur- 

 rent and excurrent water, is pointed out for the first time, though 

 perhaps slightly anticipated by an observation by Yatsu. Another 

 fact of much interest is the relation between the length of the setae 

 and the mobility of the valves upon the pedicle. When there is great 



manner in which the ridges (striae) of the shell of Terebratulina 

 coincide with the setae, though it is doubtful if there was any such 

 connection as Morse suggests between the sets and spines of such fos- 

 sil brachiopods as Productus. The movements of the brachia are 

 described as most graceful and varied. The two parts of the brachia 

 are always moved simultaneously and symmetrically. The "heart 

 of Hancock " is shown to exhibit none of the properties of a propel- 

 lant organ, and is probably connected in some way with reproduction. 

 This paper is profusely illustrated by outline drawings and one 

 plate of colored drawings, which will be a revelation to those stu- 

 dents who have never had the opportunity of viewing living brachio- 



The three papers by 



aohide Yatsu deal with Ja 



ngulas. The development of Lingula anatina 1- a con 

 of the highest importance to our knowledge of brachiopod embry- 

 ology. The earliest stages of development of this type are here 

 detailed for the first time. Even the discharge of the sexual elements 

 is noted. Females with ripe eggs will not discharge them if isolated 

 from the males, so that probably the discharge of the sperm .ut> .«s a 

 stimulus to the female to discharge her eggs. The breeding >ea>on 



, , L if tu c ir, Tanan from the middle of 



lasts about one and one half months in Japan irom 1 



July to the end of August. The gastrula is formed by invagination. 



