Botany and Zoology. 239 



under a common Endodermis. The differentiation begins in the 

 internal morphology of the organ. g. l. g. 



5. Notes on Cestoid Entozoa of Marine Fishes ; by Edwin 

 Linton.* — This second report on Fish Entozoa, has been handed 

 in for publication. 



The paper contains notes on forty-two species of Cestoids, 

 eight of which were described in the first paper.f Only adult 

 forms are described. The following changes in the nomenclature 

 of the first paper have been made. 



Phyllobothrium thysanocephalum is referred to a new genus 

 and is recorded under the name 2'hysanocephalum crispum. 

 Phynchobothrinm tenuicolle Rud. is referred to a new species 

 R. bulbifer. Mhynchobothrium bisulcatum is put in Diesing's 

 genus Tetrarhynchobothrium. The reasons for these changes are 

 given under the observations on the species. Van Beneden's 

 genus Acanthobothrium, which had been combined with the genus 

 Calliobothriimi by Diesing, is retained. The genus Eeheneiboth- 

 rium has been so emended as to exclude those species with 

 echeneiform bothria which are destitute of a myzorhynchus. 

 These are combined in the new genus Mhinebothrium. 



There are peculiar difficulties in the way of classifying the un- 

 armed Tetrabothriidm and more investigation is needed before 

 the truth is arrived at. Further investigation upon new material 

 may make it possible to unite several genera of the Phylloboth- 

 rinw. Several forms were discovered in which the bothria were 

 united into a globe or disc. These have been referred, for con- 

 venience, to a common group, to which the family name Gamo- 

 bothriidce has been given. The genera which have been referred 

 to this group differ greatly from each other but agree in having 

 the bothria united. 



One of the most remarkable of the new forms is the one I have 

 named Paratmnia medusia. This is a small tamia-like worm, 

 which, instead of having a simple papilliform proboscis, or a 

 retractile proboscis armed with hooks, has sixteen flexible tentac- 

 ular proboscides, which it can either retract, leaving a circular 

 terminal os, or extend, forming a rosette or crown of tentacles 

 like those of an Actinian. 



It is to be observed that the species which I have succeeded 

 in identifying with European species belong to hosts which, for 

 the most part, are found on both sides of the Atlantic. The 

 species described in this paper were collected in the months of 

 July and August in the summer of 1886 and 1887 at Wood's 

 Holl, Mass. During the summer of 1887 I made most careful 



* Abstract prepared by the author ; published with the consent of Marshall 

 McDonald, IT. S. Commissioner of Fish and Fisheries. The first paper is incor- 

 porated in the Report of the TJ. S. F. C. for the year 1886. Pp. 453-510. Plates 

 I to VI. 



f Lack of space makes it necessary to omit the list of species and the families 

 to which they belong. — Eds. 



Am. Jour. Sci.— Third Series, Vol. XXXVII, No. 219.— March, 1889. 

 15a 



