Systematic guide to the genera and species of Rhizocephala, with anatomical diagnoses. 



113 



Host 



Name of Parasite 



Locality 



Chlorodius areolatus 



8. pomum 





Macrophthalmus sp. 



S. alas 





Orapsus strigosus 



S. flexuosa 





Myra fugax 



8. captiva 





Lupa sp. 



8. cannata 





Pilumnus ursulus 



8. cartieri 





Lupa sp. 



S. bipunctata 





Cancer sp. 



8. exarcuata 





Thalamita sp. 



8. margaritifera 





[Thalamita sp.) 



[8. hians) 



(see Heterosaccus hians) 



Lambrus haplonotus 



S. cavolinii 





Gulf of Mexico — West Indies. 



Host 



Name of Parasite 



Locality 



Panopoeus harbitii 

 Pilumnus sp. 



8. panopoei (Gissler [17]) 



Tampa, G. of Mexico. 

 Venezuela and West Indies. 



Remarks. I need not add here any anatomical remarks, since the parasite of Carcinus 

 maenas has been minutely treated by Delage, and that of Inachus scorpio forms the subject of 

 many observations in this book. 



As far as is known Sacculina infests about 50 difFerent species of Brachyura, scattered 

 ali over the world and at ali temperatures. It is not however known to enter the arctic 

 circle. The only forni coming from really deep water is the parasite of Lispognathus Thompsoni 

 (Norman) (1180 — 1275 meters) which was shown to me by Dr. H. J. Hansen in Kjòbenhavn. 

 Otherwise the parasites may infest truly littoral crabs, or else in shallow water up to 100 meters. 



Note. In the diagnosis of the genus Sacculina, the lagenae of the roots are mentioned and also the retina- 

 cula which attach the egg-tubes to the mantle. Delage (16 pp. 450 and 529) has described these organs and to his 

 description I have nothing to add. With regard to the function of the lagenae I have been unable to establish 

 their excretory nature. A root of Sacculina neglecta with a lagena is figured on Piate 2 fig. 1. 



Genus Heterosaccus. 



Diagnosis. Similar to Sacculina, save that the mesentery is confined to the surface of the 

 visceral mass immediately round the ring of attachment, and does not stretch to the 

 mantle opening. 



Mantle opening, in consequence, widely gaping. 



Parasitic on Brachyura. Solitary. 



Zool. Station zu Neapel, Fauna und Flora, Golf von Neapel. Eliizocephala. 



15 



