1889.] NATURAL SCIENCES OF PHILADELPHIA. 95 



April 16. 



The President, Dr. Joseph Leidy, in the chair. 



Thirty-four persons present. 



The following papers were presented for publication : — 



" A contribution to the Spider fauna of the Bermuda Islands," 

 by Dr. Geo. Marx. 



"Notes on a small collection of Myriapods from the Bermuda 

 Islands," by Charles H. Bollman. 



" A contribution to the Actinology of the Bermudas," by J. 

 Playfair McMurrich, Ph. D. 



" On some new species of Mollusca from the Bermuda Islands," 

 by Angelo Heilprin. 



A Parasitic Copepod. — Prof. Leidy remarked that last summer 

 while at Beach Haven, N. J., there was brought to him from the 

 surf a living specimen of the singular, transparent fish Leptoeephalus. 

 In examining it he observed attached to the tail-fin a minute cope- 

 pod crustacean, apparently of the genus Chalimus. The parasite 

 was attached by a long filiform rostrum and resembled in this and 

 other respects more the Chalimus eeomberi, as represented by Baird, 

 in fig. 5, tab. xxxiii, of the British Entomostraca, than it does the 

 original of this species as represented by Burmeister in the Nova 

 Acta N. C. of Bonn, xvii, tab. 23, fig. 13. The species which may 

 -. be distinguished as Chalimus tenuis is considerably less 



\ than half the size of C scomberi. The cephalothorax 



nearly twice the length of the breadth, is obcordate and 

 proportionately much narrower than in the latter species. 

 The frontal segment is narrow and not prominent laterally, 

 and the biarticulate antennae are concealed beneath. 

 The abdomen, half the length of the cephalothorax, ex- 

 hibits three conspicuous divisions, and the short caudal 

 appendages end in three minute setae. Abdominal feet 

 ending in biramous leaf-like segments fringed with short 

 setae. Rostrum linear and almost as long as the cephalo- 

 thorax. Whole length 1.125 mm; length of cephalo- 

 thorax 0.5 mm ; breadth 0.275 ; length of rostrum 10.5 ; 

 length of abdomen 0.25 mm. 



The accompanying outline represents the animal mag- 

 nified fortv-four diameters. 



