82 MR. II. CHARLTON BASTIAN'S MONOGRAPH 



genera the uterus aucl ovaries are formed upon the same tyjie ; and in those excep- 

 tional cases where the posterior segment remains undevclojied, it may still be seen in a 

 rudimentary condition in the genus Tylcleuchus (PL X. fig. 113), whilst in others little 

 or no trace of it can be recognized in the adult animal. The male organs consist usually 

 of a long tube proceeding from the junction of two elongated sacs or testicles, which 

 occupies the ventral aspect of the body, and terminates at the anal cleft, or, as in 3Ion- 

 hystera ambigua and If. disjuncta (PI. IX. figs. 12, 13), a little anterior to it. In two 

 species, II. amhigua and Diplogaster JiUfovmis, I have failed to detect any horny intro- 

 mittent spicules, whilst in the remainder I have always found tv.'o equal spicules, either 

 alone or with one, two, or four accessory pieces. 



The glandular and loater-miscular systems are so intimately connected with one 

 another, that it seems best to include in the same notice what little I have ascertained 

 concerning their relations. The whole inner surface of the body is lined by a glandular 

 substance, more highly developed in some species than in others, similar to what I 

 descrilied in the Guinea"^"orm, and to what has been met with in some of the parasitic 

 Nematoids by Eberth and other observers. In addition, in several species there are 

 oife or two pyriform glandular masses connected with the vagina (PI. XI. fig. 147 ; 

 PI. XIII. figs. 189, 192), and also others near the anal cleft (PI. XI. fig. 143 ; PL XIII. 

 fig. 226), which have already been observed by Eberth, and termed by him "vaginal" 

 and " anal glands" respectively. He has also described and figured two or three elon- 

 gated sacs proceeding from the posterior extremity of the body, and has termed them 

 tail-glands (Schwanzdrusefi) : these I had observed also, but, from the fact of their being 

 most developed in those species in which the caudal sucker is largest, and from their 

 not presenting the usual granular appearance of the other unmistakeable glands, I have 

 always looked upon them rather as contractile sacs in some way connected with the 

 operation of the sucker, and shall spexik of them henceforth as sucker-tubes (PL XI. figs. 

 126, 151). In nearly all the marine species, I have recognized a glandular excretory 

 organ, 'opening by means of a long duct on the abdominal aspect of the oesophageal 

 portion of the body (PL XI. fig. 151 ; PL XII. fig. 164), but have found no structui'c 

 precisely answering to this in the land and freshwater species, though in four of these 

 genera, Tylelenclms, Flectns, AphelemJms, and Cephalohtis — the members of which all 

 possess the same remarkable tenacity of life — a modification of the same organ evidently 

 exists. In these genera I have failed hitherto to detect the entire structure, and have 

 only succeeded in recognizing the curved, more slender, and rigid duct with which it 

 terminates (PL X. figs. 79, 97, 104, 112). Two lateral cellular canals, essentially similar 

 to the peculiar fat-canals or lateral lines of the parasitic Nematoids, are met with, well 

 developed, in many species, between which and the external medium I have been enabled 

 to detect numerous communications bv means of a variable number of intearumental 

 pores'. In three of the four land and freshwater genera above mentioned I have 



' These pores seem evidently to have been rccognlzecl by Ebertli at the anterior and posterior extremities of his 

 Phanoderma hacillatum, though he put a totally diifcrcnt interpretation upon the appearances he observed, since he 

 considers and speaks of tliem as skin-glands {Ilautchiisen), he. cif. p. G. 



