16 



In 1892 I published an essay: ^Rliizorhina AmppJiscff' n. gen. n. sp. En in/ fiJ 

 Herjn/Uohiidce n. fam. Iwrende Copepod, snyltende paa Aivpelisca Imvigata Lilljeb. (Entoniol. 

 Meddelelser, 3. B. 5. Hefte p. 207—34, Tab. Ill), which in the first place contains a detailed 

 description of the above-mentioned new and very curious form, in the second place makes 

 an important contribution to the knowledge about HerpyUohius Stp. and Ltk.; finally the 

 new family HerpyUohiid<p is established, and the genera — seven in all — which can with 

 more or less certainty be referred to it, are grouped together. Two of these genera, 

 Troplumiphila M' Intosh and Oestrella M' Intosh, are described so defectively that we prefer 

 not to consider them in this place. The female of the other five genera has a globular or 

 oblong body without any vestige of mouth or limbs; posteriorly are two genital apertures, 

 each with its ovisac. The front part of the female of Bhisorhina forms a short, slender 

 stalk, which pierces the skin of the gill of its host; tlie inside of tliis stalk consists of two 

 tubes. Just beneath the skin of its host the stalk expands very much, the tubes are consi- 

 derably dilated, they separate and lamify irregularly thioughout the gill, even entering 

 somewhat into the body of the host. In the genera HerpyUohhts Stp. and Ltk. and Eury- 

 silenium M. Sars, the stalk, wliich consists of a single tube, is found on the ventral side of 

 the body, pierces the skin of its host and expands inside it like a collar, but this collar is 

 surrounded by the root of a large, oblong, foliaceous or irregulaily sausage-shaped body, 

 which is decidedly homologous with the tubes of the Rhizorhma, and, like these, has the 

 functicm of drawing nourishment from the host to the external, limbless body, whose business 

 it is to develop the eggs. In Succopsis Lev. and Bradophila Lev. Levinsen has indeed found 

 the stalk, but no body at the expanded end of it in the body of the host. However, he had 

 but slight material of both forms to work with, so 1 will now state as my peisonal opinion, 

 that a body, or one or two tubes, may have proceeded frdin the stalk into the body of the 

 host; otherwise it would be impossible to understand how the parasites could get their food. 

 Moreover, I may mention that, when (in Nov. 18i)(3) I spoke to the author. Inspector 

 G. M. R. Levinsen, about the matter, he felt inclined to share my opinion. Giard and Bonnier 

 (in their above-mentioned paper) describe a new parasite, Salenskya tuberosa, of wliich a 

 single specimen was found on Ampelisca spinipes Boeck from Croisic. They confess (p. 474) 

 that it »pr6sente certainement uue tres grande ressemblance avec Rhizoihina ampeJiftccr .... 

 et nous avous longtemps hesit6 a maintenir le genre SaJensJcyn, cree par nous (in the preli- 

 minary note] quelques mois apres la publication du travail de Hansen*. Still they tliink 

 they are justified in maintaining it, »au moins provisoirenient«, on the following basis: 



»Au lieu d'etre fix6 a son bote par des racines rappelant un pen celles de Sdccidina, 

 ou par un renflement comparable a celui des Herpi/Unhiiis, la femelle de SaJeni^l-ya possede 

 un appareil chitineux special, (ju'on pourrait rapproclier plutot de celui de Saccojisi.^: hrchclUdi.'i 



figur6 par Levinsen « (p. 475). I have just spoken of Saccopsis, and I will noAV express 



my opinion that if a specimen of Salenskya is found again on Awj). spinipes, and the part 

 (jf the host occupied by the parasite is cut otf, this part inilJ contain internal tidies exactly 



