14 C. 0. Wliitiuan 



most of the adults; conspicuously wider tlian the body; 

 well marked off; extremely variable in form. 



The propolars, as a mie, a little smaller thau the 

 metapolars; exceptionally , larger. The ventral cells 

 gen erally equal to, or larger than, the corresponding 

 dorsal cells. The 2 parapolars followed, in the young, 

 by 2 dorsal and 1 ventral eetodermal celi. 



Verruciform cells 2, or none. 



Total nnmber of eetodermal cells 24. 



Length of larger adults 5 mm, or more. 



Of 105 examples of Eledone moschata^ varying in weight from 15 

 to 940 grams. 97 contained Z)^cJ^ew^a moschaium , associated in 14 cases 

 with Dicyemennea Eledoties; and the remaining 8 contained D. Ele- 

 dones alone. Assuming that these numbers express average relations, it 

 may be said, with approximate accuracy, that in every 100 E. moschatae 

 80 contain excliisively D. moschatum^ 

 5 - - 1>. Eledones, 



15 - both species. 

 Thus 95^ of the Cephalopods would contain the first, and 20^, the 

 second species. 



When both species occur in the sanie Eledone, they are seldom 

 promiscuously associated. In 3 of the 14 instances recorded, the two 

 species were as completely isolated as of they had been living in differ- 

 ent Cephalopods; for each occupied, by ìtself, one of the two Cham- 

 bers into which the renai sack is divided by a median septum. Where 

 both species were found in the same renai Chamber, it was easy to see, 

 in most cases, that they were not indiscriminately intermingled, but 

 distributed in separate groups or colonies, each colony, composed exclu- 

 sively of individuals of one species, being confined to one, or a few 

 lobes of the spongy renai organ. In some cases only a very few scat- 

 tered colonies of one species could be found, the other species being 

 represented in great abundance. 



I bave frequently noticed even where onl}" a single species was 

 present, that certain lobes of the renai organ were beset with exception- 

 ally long individuals , which , judging from the contents of the axial 

 cell as well as the size, represented the earlier settlers. Several times 

 I bave met with young Cephalopods in which the entire renai organ, 

 with the exceptiou of one or two lobes, was free from the parasite. 

 These facts indicate that the parasites are not introduced in large uum- 



