452 W. N. F. WOODLAND 



contracted to a low eminence ') and is similarly ' versatile ' 

 in form. If, then, Linton is right in referring his species ' hexa- 

 cotyle ' and ' terebrans ' (which latter has a head ' variable, 

 subsagittate, wedge-shape or bhmtly rounded ") to the genus 

 Monobothrium, it is evident that Cooper's species must 

 likewise be referred to this genus, and ' Glaridacris ' 

 becomes a n o m e n n u d u m . 



The genus M o n o 1) o t h r i u m was created by Diesing in 

 1863 (6) as one of three genera in his family of the Mono- 

 bothria, i. e. forms with one ' bothrium * : the other two 

 genera being Caryophyllaeus, Gmelin, and Diporus, 

 Diesing. The genus Diporus can at once be eliminated as 

 solely having reference to the 'Caryophyllaeus trisig- 

 natus ' of Molin (14), a form ^ from the intestine of ' Gadus 

 merlucius ' which, in view of Molin's description and figures, 

 cannot be referred with any degree of probability even to the 

 Caryophyllaeidae and much less to any particular genus. 

 The genus Monobothrium, according to Diesing's defini- 

 tion, only differs from Caryophyllaeus in that (a) the 

 body is not ' depressum ', that (b) the head is ' subcylindricum, 

 bothrio, terminali subcirculari ' instead of being ' dilatatum 

 fimbriatum, bothrio terminali transverso bilabiato ' (definition 

 of Caryophyllaeus head), and that (c) the male and female 

 genital apertures open into a common atrium (' apertura 

 genitalis unica ') instead of opening separately on the surface 

 (' apertura genitalis feminea pene postposita contigua ") as in 

 Caryophyllaeus. Diesing describes two species of M o n o - 

 b o t h r i u m — j\I . t u 1) a (the C a r y o p h y 1 1 a e u s tuba of 

 Wagener (15) and Monticelli (16)) from the intestine of Tinea 

 c h r y s i t i s , and M . p u n c t u 1 a t u m , the ' C a r y o p h y 1 - 

 laeus punctulatus' of Molin (14) from the intestine 

 of Conger vulgaris — another indeterminate organism 

 described by this author which probably is not even a 

 Caryophyllaeid. 



The ' M o n o b 1 h r i u m t u b a ' of Diesing was considered 

 both by Wagener previously and by Monticelli subsequently 

 1 Possibly a Tetrabotliriid scolex, as Monticelli suggests. 



