natural sciences op philadelphia. 125 



Entomostraca. 

 limulus polyphemus.' 



Common, but much less abundant than further north. It may- 

 be taken at any season, but is especially numex'ous in May, when 

 it resorts to the shoal water about the harbor to spawn. About 

 the middle of this month hundreds were noticed on Bird Shoal, 

 these mostly copulating or seeking to do so ; and all the females 

 examined were laden with eggs. One specimen taken presented 

 a curious monstrosity, having the tail bifurcated at the extremity 

 for over an inch. One of the forks was rather smaller than the 

 other, and stood out more obliquely from what appeared to be the 

 proper termination. 



CiRRHIPEDIA. 

 Ealanus eburneus? 



In profusion, on all hard submerged objects. 

 Two other species of cirrhipeds occur, chiefly, it would appear, 

 on wood, &c., that has floated from some distance southward. 



ANNUL AT A. 



BRACHI0P0DA.2 

 Lingula pyramidata, Stimp. 



This animal can be procured in any desired numbers, with little 

 trouble, in a particular part of the harbor. After numerous trials, 

 the best place was found to be the southern side of Bird Shoals 

 (side next the fort), and in a straight line between the flagstaff 

 upon the fort and the large building at the eastern extremity of 



' On the development of this animal, see Lockwood, S., "A Contribution 

 to the Natural History of the King Crab," read October, 1869, N. Y. Lye. 

 Nat. Hist.; and " The Horse-Foot Crab," Am. Nat., IV., July,- 1870, p. 357 ; 

 and A. S. Packard, jr., abstract of a paper read before the 19th meeting of 

 the A. A. A. S. in the Am. Nat., IV., October, 1870, p. 468. 



2 Mr. E. S. Morse's discussions of the position and relations of the group, 

 as "a division o{ Annelida,'''' which have attracted so much attention, will 

 be found in the Am. Nat., IV., July, 1870, p. 314; Am. Journ. Sc. and 

 Arts., 1870, (abstract from Pr. Bost. Soc. N. H.) ; Am. Nat., IV., Oct. 1870, 

 p. 493 (abstract from Proc. of 19th Meeting of A. A. A. S). An abstract 

 of a paper by W. H. Dall in the same number of Nat., p. 510, gives an op- 

 posite view of the case. Prof. W. C. Kerr (abstract of a paper in Am. 

 I(at., Nov. 1870, p. 571) ascribes the origin of theCarolina phosphates to 

 Lifigula. 

 1871.] 



