Dr. David Sharp's Studies in Rhynchophora. 217 



we call the struts of the median lobe ; Lindeman and 

 Niisslin call them " Ffisschen," Verhoeff and Hopkins 

 " femora " : in Latin diagnostic I call them " temones." 



These struts are present in all Rhynchophora ; * and 

 though wonderfully constant in the same species, they 

 display much variety in the different forms. They arc 

 certainly of considerable taxonomic importance. Some- 

 times they are so short (Lixidae) that they escape notice 

 it a shore portion of cm is left on the preparation. In 

 other cases they are very long (in Cycloterinus foveatus, 

 Kolbe, they extend far into the prothorax and are so 

 slender that the aedeagus can only be extracted with greal 

 care). The form of the struts is also very constant in the 

 same species. They are definitely elongations of the mem- 

 brane, tubular, and tilled with chitin ; in certain cases this 

 structure is evident ; in some forms they appear to be dis- 

 connected from the body, but there is always a membranous 

 connection, though the chitin may be deficient for a brief 

 space. Such cases occur when the struts come off with a 

 great elbow from the lobe (cf . Sitones). The struts are some- 

 times quite short, and assume the form of callipers ; but so 

 far as I know this is only the case in Lixidae.^ The struts, 

 besides being areas for muscular insertion, seem to be, to 

 a certain extent, a protection to the invaginated sac when 

 this extends basally beyond the body of the lobe. When 

 the sac is elongate the struts are sure to be long. The 

 composition of the body of the lobe shows important 

 distinctions that are, I have no doubt, of taxonomic im- 

 portance ; see as to this Calandridae, Brenthidae, Rhina, etc. 



The median lobe does not enter into the genital tube 

 of the female, but only opens its terminal cloaca (not the 

 internal cavity called by Stein the cloaca). On the dorsal 

 surface of the median lobe, more or less close to the apex 

 of the lobe (sometimes at the apex, as in fig. 3), there 

 will be seen an area evidently different from the con- 

 tiguous parts : this is the place where the evagination of 

 the sac occurs, and has been called the median orifice, but 

 is not an orifice, but only the spot where the sac is 

 invaginated. or. as the case may be, inverted. 



* They are not present in Platypus; the projections there found 

 being of a different nature, as I have previously stated. 



f In Hopkins' iigures of Pissodes the struts are depicted as 

 amalgamated at their termination : this js a mistake, nothing of 

 the sort occurs in any Ehi/nchophoron, 



