06 The American Naturalist. [January, 



as the " lateral diameter." It is impossible to mention here all of the 

 curious and interesting species Linton has described ; in several species 

 of Dibothrium, for instance, the uterus empties dorsally, a point about 

 which one would be inclined to be very sceptical, were it not that Lin- 

 ton gives drawings of the animals and exact measurements of the 

 apertures. In one of his papers Prof. Linton determines the white 

 pelican (Pelecanus erythrorhynchus) as the final host of Dibothrium 

 cordiceps Leidy, the larval stage of which is found in the trout (Salmo 

 mykisi) of the Yellowstone Park. The reviewer must differ from Prof. 

 Linton in the interpretation of cysts in which these larvse are found 

 Linton interpreted them as blastocysts, but the histology described by 

 the author gives more the impression that they are connective tissue 

 and since the Keviewer has examined some specimens kindly sent to 

 him by Prof. Linton to determine this question, he does not hesitate to 

 slate that we have connective tissue cysts of the host before us, instead 

 of blastocysts. This point is very important, for were it a blastocyst as 

 Prof. Linton thought, this species would form an exception in the family 

 Bothriocephalidse, for the blastocyst would of course be homologous to 

 the cysticercus of Tseniidse and the head would form in much the same 

 manner. As it is, not the cyst, but the enclosed larva, is the homologon 

 of the cysticercus. 



The family Taeniidae has been undergoing considerable revision at the 

 hands of the noted French zoologist, R. Blanchard. In a work (112 pp.) 

 entitled Histoire zoologique et medicale des Teniides du genre Hymeno- 

 lepis, Paris, 1891, Blanchard separates all these tape worms from the ge- 

 nus Taenia, which have three testes in each segment, with genital pores on 

 the left border (for further particulars of the diagnosis, see the original). 

 Hymenolepis nana and H. diminuta are of particular interest since 

 they occur in man, and H. murina (according to Grassi identical with 

 H. nana), since Grassi has shown that in this form we have a remarkable 

 exception to the rule of development of the Tseniidae, in that E. 

 murina develops indirectly but without change of host. The following 

 is a synopsis of the species admitted by Blanchard to the genus 

 Hymenolepis. (See Table on pages 67 and 68.) 



In his notices Helminthologiques (Mem. de la Soc. Zool. de France, 

 1891, p. 420-480) Blanchard separates those members of the genus 

 Taenia which have armed suckers into three new genera. 1, Echino- 

 cotyle R. Bl., '91. Rostellum with 10 large hooks, each sucker with a 

 circle of spines on the edge and a longitudinal row in the middle, etc- 

 2, Davainea R. Bl. and Railliet '91, Rostellum or infundibuluna W»* 

 double row of hooks, each sucker surrounded with several circular 

 rows of hooks. Corpuscles made up of conglomerations of eggs are 



