22 PROCEEDINGS OF THE ACADEMY OP [1884. 



character of the latter, and the method of its construction. In 

 its earliest stages it is a transparent, smooth, and homogeneous 

 slime-like excretion, within which the worm may be very clearly 

 seen, as it works its way forward or drags itself backward by means 

 of its podal hooks and* spines. Later on, the anterior extremity 

 thickens and becomes more and more opaque, and, as Dr. Leidy 

 has observed, " feebly annulated," presumably from the adherence 

 of effete particles, and their compression by the repeated with- 

 drawal of the ciliated tentacles into the mouth of the tube. This 

 method of prolongation must continue during the residence of 

 the worm, and in consequence, if supported, it may sometimes 

 reach a length which is several times that of its inhabitant. 



January 29. 

 The President, Dr. Leidy, in the chair. 

 Thirty-three persons present. 



Fossil Bones from Louisiana. — Prof Leidy directed attention 

 to a collection of fossil bones, which have been submitted to his 

 examination by the Smithsonian Institution. They were obtained 

 by Mr, William Crooks, at the mine of the American Salt Com- 

 pany, near New Iberia, La. They chiefly consist of remains of 

 Mastodon americanus, of Equus major, of Equus, not distinguish- 

 able from those of the domestic horse, and of Mijlodon harlani. 

 Of Mastodon the collection contained well preserved molar teeth, 

 and characteristic fragments of bones. Of the Equus major, 

 there are vertebrae, fragments of long bones, and a number of 

 teeth. The molars are characterized by their comparatively large 

 size and complexity of arrangement in the enamel folding, espe- 

 cially of the upper molars. Of 3Ii/lodon there are several molar 

 teeth, vertebrae and other bones, mostly fragments. Among the 

 bones are two mature and well-preserved tibiae, the best specimens 

 yet discovered of the species. They are identical in form and 

 size with those of M. rohudus ; indicating M. harlani to have 

 been a species of the same size as the former. The extreme 

 length of the tibia internally is nine inches ; breadth across the 

 head, seven inches ; across the distal extremity, five and one-half 

 inches. Further collections were anticipated from the same 

 locality. 



Foraminifera in the Drift of Minnesota. — Prof Leidy stated 

 that he had recently received for examination, from Mr. B. W. 

 Thomas, of Chicago, several glass slips with mounted specimens 

 of sand. These were obtained by washing clay from the boulder 

 drift of Meeker Co., Minnesota. In the specimens, Prof. Leidy 



