12 



The hooks and plates, which form such a remarkable feature 

 of the Synaptse, are similar to those of <S. Dui^erncBa^ as de- 

 scribed by Quatrefages. They differ in having the external 

 curve of the hamecon smooth, as also the head, which joins 

 the supporting plate, and in the arrangement of openings 

 through the plate. They are sometimes wanting or imper- 

 fectly formed, the development of the plates being apparently 

 subsequent to that of the hooks. 



This species is found abundantly in Boston Harbor, on Bird 

 Island, and the adjacent shallows, and as it has been obtained 

 also at Sag Harbor, L. I. as well as at Provincetown, its range 

 is doubtless somewhat extensive. It inhabits the sandy and 

 muddy bottom, creeping by means of its tentacula and the hooks 

 with which its body is covered (as in others of the genus) and 

 which often cause it to adhere to the finger like the seeds of 

 many plants. When kept in confinement it detaches piece 

 after piece of its body by contractions of the transverse muscles 

 till frequently only the circle of tentacula is left, and yet life 

 is not destroyed. 



Mr. William Stimpson presented a paper containing 

 notices of several species of Testaceous Mollusca new to 

 Massachusetts Bay, including new species. 



Since the publication of Dr. Gould's admirable Report on the 

 Invertebrata of Massachusetts, the more extended investigations 

 to which that work gave rise, from the increased interest with 

 which it invested them, have doubtless been the means of adding 

 to our Fauna many species not before noticed. But although, 

 as may be seen from published notices, our catalogue of Articu- 

 lata and Radiata has been much extended, I cannot find any 

 notice of additions among the testaceous mollusks. Such have 

 probably occurred, however, to many of our Naturalists, and I 

 have been induced to mention here those which I have met 

 with, in hopes that others will in the same manner aid in efforts 

 to make our catalogue complete. I have here enumerated and 

 remarked upon twenty-five species not before observed in 

 Massachusetts Bay, about twe-nty of which are new to the 

 State. 



