155 



Alaska, a genus Amicula was constituted by Gray, characterized by 

 covered valves and regular pore-tufts. The elder Sovverby figured the 

 Emersonii as vestitus in his Conch. Illustr. Hence Dr. Gould natu- 

 rally looked for the pore-tufts, and found them. Having received a 

 fresh specimen from Dr. Stimpson, I could not find them. I wrote 

 to Dr. Gould, who sent me his type specimens with sketch of regular 

 pore-tuft's, as he saw them ; but still I could not. He died without 

 clearing the difficulty; and I presumed there might be two species, 

 one with and one without pores. But after examining both northern 

 and southern suites of specimens, I feel confidence in stating that 

 there are no true pores; but simply a profusion of hair bunches, 

 generally very irregular, but sometimes, in early stages, more con- 

 spicuous at the sutures. I propose, therefore, to keep the name 

 Amicula for the Alaskan pore-bearing species ; and to name this (with 

 the Alaskan Pallasii), Slimpsoniella, in honor of one of the best natu- 

 ralists born in New England. In this genus, as in Trachijdermon, the 

 faeces are expelled through slits close to the caudal lobe, one on each 

 side. When at rest, the creature makes a posterior fold in the girdle, 

 corresponding to the wave in the posterior valve. 



I should be extremely indebted to any gentlemen who would lend 

 me unusual Chitons for examination, previously to the publication of 

 my " Contributions towards a Monograph of the Chitonidse" by the 

 Smithsonian Institution. There is also a great field open for investi- 

 gation to all those who can examine living chitons, or even dissect 

 alcoholic specimens. It is known that the external characters are 

 not coordinate with the internal ones ; it remains to be found out 

 whether either of them correlate with the anatomical characters of 

 dentition, gills, vent, etc., which ought to furnish the best divisions 

 iu arranging this difficult group. 



The Secretary, Mr. JOHN ROBINSON, gave an interest- 

 ing account of the botanical work in the morning. His 

 remarks were chiefly confined to a description of the 

 ferns found during the excursion, as follows: 



Among the rarer ferns in this region is Pliegopteris 

 polypodioides , a fine specimen of which was collected by 

 Miss Page this morning. This and its associate, P. 

 dryopteris, are only to be found in a few localities in this 

 county, while north and south they are very abundant, 

 particularly near mountain streams. Of the other New 

 England ferns that are rare, or not as yet found here, 

 may be enumerated Stmthiopteris Germanica, Ophio- 



