REPOET ON THE ANOMURA. 53 



Two of the genera, viz., Ostraconotus and Tylaspis, agree in having the posterior 

 part of the carapace broad and firm, and the abdomen poorly developed, characters in 

 which they diflfer from all other Paguridse. 



Genus Diogenes, Dana. 



Diogenes, Dana, U.S. Explor. Exped., vol. xiii., Crust., part i. p. 438, 1852. 



Stimpson, Proc. Acad. Nat. Sci. Pliilad., p. 70, 1858. 

 „ Heller, Crust, sudlichen Europa, p. 1G9, 1863. 



Haswell, Catal. Austral. Crust., p. 156, 1882. 

 „ Henderson, Proc. Eoy. Phys. See. Edin., vol. ix. part i. p. C6, 1886. 



Front with a movable rostriform process situated between the ocular peduncles, but 

 distinct from the rostrum. Antennal acicle with a broad base, occasionally bifid ; the 

 flagellum ciliated and frequently short. Chelipedes unequal, the left larger ; fingers 

 moving in an oblique plane. Second and third j)airs of legs with long dactyli ; the 

 fourth pair subcheliform. 



Diogenes custos (Fabricius). 



Pagurus custos, Fabricius, Suppl. Ent. Syst., p. 412, 1798. 



„ „ Latreille, Hist. Nat. des Crust, et Insect., t. vi. p. 165, 1802. 



„ „ Olivier, Ency. Metli., t. viii. p. 644, 1811. 



„ „ Milne-Edwards, Ann. d. Sci. Nat, ser. 2e, t. vi. p. 284, 1836; Hist. Nat. 



des Crust., t. ii. p. 236, 1837. 

 Diogenes custos, Dana, U.S. Explor. Exped., vol. xiii.. Crust., part i. p. 439, pi. xxvii. fig. 10, 

 1852. 



„ „ Stimpson, Proc. Acad. Nat. Sci. Philad., p. 83, 1858. 



„ „ Hess, Decapoden-Krebse Ost-Australiens, p. 35, 1865. 



„ „ Haswell, Catal. Austral. Crust., p. 157, 1882. 



Habitat. — Port Jackson ; depth, 2 to 10 fathoms. An adult male. It is recorded 

 by Stimpson from the same locality, and by Dana also from New South Wales. 

 Diogenes custos extends from the Australian seas to the shores of India. 



Diogenes brevirostris, Stimpson (PI. VI. fig. 3). 



Diogenes irevirostris, Stimpson, Proc. Acad. Nat. Sci. Philad., p. 83, 1858. 



„ „ Studer, " Gazelle " Crust., Abhandl. d. k. Akad. d. Wiss. Berlin, p. 23, 



1883. 



Habitat. — Simon's Bay; depth, 10 to ,20 fathoms. A female with ova, in an 

 imperfect state of preservation. ' 



Stimpson's types were from the above locality. This species may eventually j^rove 

 to be .synonymous with Diogenes varians (Costa), as the latter appears to be subject to 

 considerable variation. The Challenger specimen differs, however, from the typical form 



