89 



tember last, he again met with several specimens, about six 

 inches long, being somewhat smaller than those with which he 

 first became acquainted of that genus. They were greenish 

 brown anteriorly, and brownish green posteriorly ; provided with 

 thirteen pairs of branchial tufts, the anterior and posterior ones 

 being less developed than those in the middle of the series. Six 

 pairs of rudimentary podal appendages were to be observed in 

 front of the foremost branchise ; the caudal region slender, and 

 constituting about two fifths of the entire length, and composed 

 of from forty-five to forty-seven rings, narrowest posteriorly ; its 

 surface covered with roundish granules of a warty appearance, 

 from near its origin to its lip. The body, properly so called, and 

 the cephalic region, were smooth, the latter exhibiting an irreg- 

 ular meshwork of lines, visible to the naked eye. Proboscis 

 granular. Dorsal region marked by a conspicuous smooth line, 

 which, upon the cephalic region, subdivides into a left and right 

 branch, uniting again anteriorly. The name of Arenicola natalis 

 is proposed to distinguish henceforth this species. Its affinities 

 are with A. piscatorum, having the same number of podal append- 

 ages and gills. The cephalic region, however, instead of being 

 so decidedly club-shaped as in the latter, is rather tapering, as 

 well as the caudal region. The reticulation of its anterior region, 

 and the dorsal line alluded to above, will serve as specific fea- 

 tures. 



Mr. Girard said he had also found on Chelsea beach a speci- 

 men* of Placohranchus, about a quarter of an inch long, rather 

 stout, blunt anteriorly, and tapering posteriorly, and of a deep 

 greenish hue. He regretted that, on being carried home, the 

 animal died, and thus a more complete description of it he could 

 not now furnish. He would affix to it the name of Placobranchus 

 simplex, being the first species of the coast of the United States 

 to which a name had been applied, and he would avail himself 

 of another opportunity for a critical examination of its specific 

 characters. 



Mr. Girard further remarked that while at Cambridge, he came 

 across a specimen of Storeria Dekayi, the abdominal region of 

 which presented a hue very similar to that of Storeria occipito- 

 maculata ; it was salmon-colored throughout, a little lighter under 



