3-2(> Dr. v.^- the Rvv. S. Gralmm Biadr-BIiks on 



is often nssociatcil witli Ciiliniiroiiihis a'lJcuvum, and its usual 

 Iiabitat is Ix'twccn the bark and trunk ol* rottini;- lo<i-*. 



ViTV tVw specimens (no achilt J), l>ak.'\vi'll cHstiitt, our- 

 solvos,' liUS. 



Family Polydesmidae. Leach (ox ii.), 1814. 



Genus Polydesmus, Latreille, 1802 vt 1804. 



11. P. complanatus (Litnir). 



1:^-28-5 mm. 



This large flat-backed millipede is common in tlio Uritish 

 Isles. Its gonopod.s are distinctive. The genus has twenty 

 body-segments. 



■^2 c{ c? , T'lie Winnats, Casth'ton, R. S., in a recent year 

 (./.), G. 3149; *2 (J c? arful juniors, Cave Dale, 11. S., "in a 

 recent year (J.), G. 3136; *c? c? ? ? , in a collection from 

 Dove and Mill Dales, R. S., 21/iv./14 (J.); (?, near the 

 K. Dove, ourselves, ix./16 ; Bakeuell, ourselves, 4/vi./l<S ; 

 1 S, Manners Wood, near Bakewell, W. B. ^- S. G. H.-H., 

 G/vi./18 ; Bakewell district, oiir.selves, 1018. 



12. r. coriuceus, Porat. 



12*5 mm. 



This species is smaller than P.eomplanatiis, also the males 

 have distinctive gonopods. A male from Great Longstone 

 which we dissected for careful dia^rnosis was 125 mm. lonoj. 



l^akewell di.^trict, ourselves, 1918. 



13. P. denticulatus, C. L. Koch, 1847. 



10-16 mm. 



Again the gonopods o£ the male are diagnostic. In tliis 

 character we did not find the male recorded below quite 

 tyi)ical. The slight diff<'rence, however, is probably no more 

 than an individual ))eculiarity in the specimen in question. 

 ()u the whole the condition ot the gonopod is similar to that 

 of the preparation given by Dr. Biolemaini in figine 34 in 

 the xviith. paper of the ' Biospeologica' series (7). In our 

 examp e the secondary ramus is arched mucli as tiiat i< in the 

 fig. 34 cited. To adopt the lettering used by Dr. Biolemann, 

 its external ap[)endix ( p) is well developed, bioad, slightly 

 arched, and lurnished with a well-marked sharp tooth ( //) 

 near the base, as in figure 34 (op. cif.). The individual 

 difference we have noted {(inte) consists in the presence ot a 

 frecond small tooth on the internal face of the distal part of 



