620 F. A. POTTS. 



2. GiAKi), A. — "Sur la castration parasitaire cliez I'Eiipagurus Bern- 



liardus et chez la Gebia stellata," 'C. R. Acad. Paris,' t. civ, 

 p. 113. 



3. GiARD, A. — "La castration parasitaire (nouvelles reclierclics)," ' Bull. Soc. 



Dep. du Nord,' (3), i, 1SS8, p. 12. 



4. Heubst, C. — 'Formative Reize,' 1901. 



5. PxiiEZ. — " Des EiFets du parasitisme des Stylops sur les Apiaires du Genre 



Andreiia" (Act. Linn. Soc. Bordeaux, t. 40). 



6. SciilMKEWiTSCH, \V. — " Ucber die Untersuchungen von J. 0. Pekarsky ; 



ueber die Entwieklung von Peltogaster paguri," ' Trav. Soc. 

 Natural Petersbourg,' vol. xxviii, p. 218, 1898. 



7. Smith, Geofpkey. — "Note on a Gregarine which may cause the Parasitic 



Castration of its Host," 'Mitt. Zool. Slat. Neapel,' 17 Band, 3 Hel't, 

 1905. 



8. TuoMPSON. — "Metamorphosis of Hermit Crab," 'Mem. Boston Soc. Nat. 



Hist.,' 1903-4. 



EXPLANATION OF PLATES 33 and 34, 



Illustrating Mr. F. A. Potts paper ou '^The Modification of 

 the Sexual Characters of tlie Hermit Crab caused by the 

 Parasite Peltogaster (castration parasitaire of Giard)." 



In all cases the first three abdominal appendages only are figured ; they 

 are denoted respectively a, b, and c. 



PLATE 33. 



Fig. L — Normal male: abdominal appendages. 



Fig. 2. — lufected male : abdominal appendages. Stage 1. 



Fig. 3. — Infected male : abdominal appendages. Stage 2. 



Fig. 4. — lufected male : abdominal appendages, Stage 3. 



Fig. 5. — lufected male : abdominal appendages, Stage 4 (appendages 1 and 

 3 only are figured). 



Fig. 6. — Normal female : abdominal appendages (appendages 2 and 3 only 

 are figured), e.r. External ramus, i.r. Internal ramus. 



