( 22 ) 



Never do all the abdominal segments bear paired appendages : usually 

 the appendages are on the left side only, and are present on somites 2-5 or 

 3-5 : occasionally the first, or first and second, abdominal segments of the 

 male, and the first abdominal segment of the female carry a pair of append- 

 ages modified for sexual purposes. 



The telson is usually more developed on the left side than the right, as 

 also are the caudal appendages or uropods. 



The gills may be phyllobranchiae or trichobranchiae, or may be inter- 

 mediate between the two. 



Milne Edwards and Bouvier divide the Pagurtda mto two sections, 

 namely, Mtxtopagurints ( Mixtopagtiriaa), in which the external maxillipeds 

 are juxtaposed at base, and Eupagurinte [Eupaguricea), in which the bases of 

 the external maxillipeds are widely separated by a sternum. 



As the Mtxtopagurinte of these authors also includes the symmetrical 

 forms here separated as Pylochelidtg, I prefer to adopt the scheme of Ortmann, 

 who divides the family into two subfamilies, namely, Pagurince (equivalent 

 to the Mixtopagurinae minus the Pylochelidse) and Eupaguriua. 



In this place, and before the systematic consideration of the Pagiiridce 

 is undertaken, Glaucothoe may be mentioned. 



Glaucothoe has by various authors been regarded as a distinct genus and 

 ranked either with the Thalassinoids, or later, with the Paguroids ; but it has 

 held a disputed position among the latter ever smce Spence Bate advanced 

 the opmion that it is merely one of the larval stages of Pagurus. There is 

 now plentiful evidence as to the existence of a glaucothoe-stage in the post- 

 embryonic development of Pagnridce, and the luminous researches of 

 Bouvier (Ann. Sci. Nat. Zool., 7 ser., XTI., 1891, pp. 65 — 82) seem to estab- 

 lish the view that the " species " described under Glaucothoe are really only 

 persistent larval forms of different Paguroids. Such persistent larva;, or 

 larvae which in the course of their development have failed to follow the 

 normal line of metamorphosis, but without complete arrest of growth in 

 consequence, are not unknown in other groups of aquatic and amphibious 

 animals. 



Glaucothoe, Edw. 



Glaucothoe, Milne Edwards, Ann. Sci. Nat. Zool., XIX., 1830, p. 334; and Hist. Nat. 

 Crust, I!., 1837, p. 306; and in Cuv. R^gne Anim.. Crust. (3rd Edit.), pi. xliii , fig. 2. 



Prophvlax. Latreille, in Cuvier R^gne Anim., 2nd Edit., IV., 1830 p. 78. 



Glaucothoe, Dana, U. S. Expl. E.^p. Crust., Pt. 1, 1852, p. 509: Spence Bate. Ann. 

 Mag. Nat. Hist. (4), II., 1868, p. 115: Faxon, Mem. Mus. Comp. Zool., Harvard, IX, No. I, 

 1882, pi. xiii., fig. 5: Henderson, Challenger Anomura, 1888, p. 83 : Bouvier, Ann. Sci. Nat. 

 Zool. (7), XII., 1891, pp. 65-82. 



