572 I'rof. A. Aleck on 



the liali'way-liouse at a time wlu ii tlic primitive crabs, which 

 arc iio\v represented ])y a furtive remnant, were a more 

 nourishing stock, 



I may mention that tliis interpretation is confirmed by 

 the distribution (tabuhitcd in my ' Catah)j^ue of Brachytira 

 Pr!U)i};enia in tlie Indian Museum^) of three other families 

 oi ])iimitive eral)s, namely the llomolodromidie, the Ilomo- 

 lid;e, and the Latreillidee ; and thou<;h I must add that it 

 finds no })artieular corroboration in the distnl)utiou of the 

 iJynomenidie and Dromidse (which are also primitive groups 

 related to the Homolida;), I may suggest, as a necessary 

 explanation, that the Dynomenidse and DromidiC are very 

 hugely shallow-water and littoral i'orms, whose distribution 

 may have since been influenced by causes which would not 

 aii'cct sijccies that had become adapted to deep-sea conditions. 



1 may also refei* for corroborative evidence in this con- 

 nexion to my paper in the 'Annals' for October 1904 on the 

 distribution of the Amphibians of the family Caeciliidte, in 

 M hieh also the suggestive geographical relations of the Indian 

 suljlittoral Paguridai are tabulated. 



4. Remarks o\ the Genus CriroyoMOPs. 



lu the ' Bulletin de la Societe Philomathique de Paris/ 

 8 ser. torn. ix. (1896-1897), and again in the Keport on 

 the Dromiacea and Oxystomes dredged by the ' Blake,' 

 published in 1902, Professor Bouvier, who could not have 

 seen my paper ou Indian Oxystoniata, published in the 

 ' Journal of the Asiatic Society of Benjjal ' for 1896, com- 

 plains that the affinities of (ywononiops have i\ot been made 

 clear ; so I take this opj)ortiinity of re-characterizing this 

 gcims and of adding the necessary information regarding the 

 structure of its mouth-])arts, the distribution of its gills, and 

 the position of the openings of the oviducts. 



Cymonomops, Alcock. 



Cymoiwmops, Alcock, Ami. & Mag. Nat. Ilisl., May 1894, p. 400, and 

 Jouni. Asiatic ^oc. IJeiigal, vol. Ixv. jit. 2, no. 2, ISIKJ, p. 'J^tJ; 

 Jiouvier, loc. cit. 



Carapace almost semicircular in outline, not concealing 

 the anterior abdominal terga, its grooves and regions fairly 

 well defined. 



The front consists of a nai-iow rostrum, not much breaking 

 the general contour of the eara])aee and ending in two teeth. 



