

142 Bibliographical Notice. 



Among some soundings obtained by the Rev. R. Boog 

 Watson from Madeira, are several specimens of young shells 

 in which the larval shell or pullus is still complete. These 

 larval shells are what were considered to be Sinustgerce. 



Thanks to this gentleman's courtesy, I am enabled to figure 

 one of these specimens, showing the pullus and the continued 

 growth of the shell. In this species the pullus is a Sinust- 

 gera, intermediate between S. Huxleyi, Forbes, and S. micro- 

 scopica, Gray ; and in the figure the claw-like lobes from which 

 the shell has continued its growth are easily recognizable. 

 The adult shell of this species is in all probability a Purpura, 

 and very likely P. hcemastoma, Lamk. 



Among these soundings there are also several specimens of 

 another species, the pullus of which is closely allied to S. 

 cancellata, d'Orbigny ; but with regard to the adult state of 

 this shell there is more uncertainty ; it may perhaps prove to 

 be a Pisania. 



Sinustgera perversa. Craven, is the young of a Triforis, or of 

 some allied genus in the Cerithiidse. 



Further observations will no doubt show the shells of the 

 Sinusigerce to be the pulli of many and varied genera. Per- 

 haps also these pulli, when driven far away from shore by 

 currents or storms, pass their existence in this larval state, 

 and never increase or reach maturity, and only those more 

 fortunate in being in shallow waters near shore sink to the 

 bottom and there continue their growth and development. I 

 believe this fact to have been ascertained with regard to some 

 other oceanic forms. 



Should this be the case, it would account for the vast num- 

 bers of these shells, constant in their dimensions in each 

 species, which are found both on the surface of the open 

 ocean and in a dead state at great depths. 



At any rate, the genus Sinustgera must now cease to exist, 

 and time only will show the species of Gasteropods of which 

 the various so-called species of Sinusigera are the young. 



BIBLIOGK 



Domest 



auction to Human, Veterinary, and Comparative Anatomy. By 

 B. G. Wilder and S. H. Gage. 8vo. Pp. 575, 130 woodcuts, and 

 4 plates. New York and Chicago, 1882. 



classi 



anatomy 



