288 ARTHUR E. SHIPLEY. 



contents of the golden egg-shell stained uniformly and deeply, 

 so that no nucleus could be detected. In bulk the egg in 

 the egg-shell surpassed the ripe ova in the yolk-gland ovary 

 complex by some five or six times; this is almost certainly due 

 to the addition of the yolk. On the other hand, the golden 

 case may have been an egg capsule, and contained more than 

 one egg. I rather gather that Russo takes this view. 



II. Nematoda. 



In 1854 Dr. Leydig^ described some nematodes belonging 

 to the genus Oncholaimus which he had found in the 

 alimentary canal of Echinus esculentus. The parasites 

 were 4 mm. long, thi-ead-like and pointed at both extremities. 

 The oral cavity was provided with a certain toothed and ridged 

 armature in the shape of thickenings of the cuticle prolonged 

 from the firm cuticle covering the body. The oesophagus 

 was long, and posteriorly enlarged^ but nowhere did it form 

 a bulb. The intestine ran in a straight line to the anus at 

 the base of the tail, and had a brown colour due to pigmented 

 gi-anules which crowded the cells. The ovary had an anterior 

 and a posterior branch, and each branch terminated in a line 

 which doubles back and ends near the genital opening about 

 the middle of the body. The ripe egg was of considerable size 

 and of oval shape. The oviducts united to form a sharply 

 defined vasfina. The cuticle had longitudinal striations. 



Dr. Ley dig suggested the name Oncholaimus echini 

 for this parasite. 



The only other nematode that I find mentioned as coming 

 from within the body of Echinus esculentus is the large 

 green nematode of Silliman, which presumably — it is not quite 

 certain — came out of one of these creatures taken at Roscoff. 



A year or two ago Mr. A. J. Smith, assistant at the 



Marine Biological Laboratory at Plymouth, found two or 



three very long nematodes in the perivisceral cavity of an E. 



esculentus at Plymouth, which he sent to me for investiga- 



1 'Mailer's Archiv,' Jtihrgaiig 1854, p. 291. 



