5Q 



General Notes. 



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uaiy, 



our parasites need to do in order to get at the juices of their 

 host, is to cut through the lamella next to them and they have an 

 abundant supply of food always at hand. It appears that Van 

 Beneden, the elder, regards them, on the authority of A. Agassiz, 

 as messmates, but from the foregoing recital it would appear that 

 they are more or less truly parasitic in habit. It appears that 

 other crustaceans are infested by planarians, and Professor Leidy 

 has described a parasitic genus, Bdellura. 



On the specimen of Limulus examined by me there were three 

 well-marked types of egg capsules. The first, represented in 

 Figs. 1-4, enlarged sixteen times, measured about a twelfth of an 

 inch, or about a line, in length, and usually contained from two 

 to four embryos. The branches of the gastric cavity are separate 

 posteriorly in the embryos, but afterward become joined, as 

 srrown in Fig. 10, supposed to be the adult of this second form 

 This form has a pair of eye spots developed at a very early period 



which are retained when hatched. The mode of segmentation of 

 the eggs is very difficult to make out in the capsules, as the indi- 

 vidual ova are very strongly pigmented, and consequently almost 

 opaque, so that the contours of the cells cannot be discerned. 



The second form, represented in Figs. 5-7, enlarged sixteen 

 times, is much smaller but similar in structural features to the 

 preceding. The capsules measure about one-twenty -fifth of an 

 inch in length, and contain usually two eggs or embryos. At 

 first the ova occupy each one of the ends of the capsule, as 

 shown in Fig, 5, but after the young worms have developed 

 somewhat they usually lie along side of each other lengthwise of 

 the capsule. They frequently change positions, however, at this 



