1871.] J. Wood-Mason— On Telphusidce. 191 



association with the Grapsid^e in the Catometopa, and placed them 

 in their more natural position next to the Cancroidea typica under 

 the legionary name of the Telphusinea gr Cancroidea grapsidica, 

 on the ground that they possess the same number of branchiae, 

 a similar abdomen, and have the male copulatory organs similarly 

 inserted in the basilar joint of the last pair of ambulatory legs, 

 and covered from their origin by the abdomen. The Telphusid^:, 

 however, evidently constitute a transition between the Cancroidea 

 typica and the grapsoidea, as may be seen from their general 

 Grapsoid form, 



The family Telphusid^; is divisible into the following genera and 

 subgenera : — 



Telphusa, (Syn. Geotelphusa) : Sab. Southern Europe, Africa, 

 India and its islands, Burma, China, Australia, Chili. 



Paratelphhsa : Sab. South-Eastern Bengal, Assam, Burma, 

 Pegu, China, Siam and the Indo-Malayan Archipelago. 



Boscia, Dilocarginus, Sylviocarcinus, Potamocarcinus, Tricho- 

 dactyltjs, &c. : Sab. Tropical America. 



Deckenea : Sab. Eastern Africa (Zanzibar). This genus resem- 

 bles the Telphusidce in the development of the branchial regions 

 and in the position of the male copulatory organs, but the structure 

 of the external maxillipedes and position of the efferent orifices of 

 the branchial cavities recalls the disposition of these parts in the 

 Oxystomatous Crustacea. 



Of the developmental history of the Telphusid.e nothing is, I be- 

 lieve, known, and I extremely regret that I have not yet had an op- 

 portunity of making observations on this head ; but this I can say, 

 that the ova are of large size and few in number. Whether, however, 

 direct development without metamorphosis is correlated with the 

 large size of the eggs and their fewness in number, as in the single 

 instance amongst the Brachyura (in Gecarcinus), investigated by 

 Prof. Westwood, or whether the young commence their existence 

 as Zoeas, as in another species of the same genus, noted by Thom- 

 son, must be left for future observations. Arguing from what 

 happens in the case of fresh-water branchiferous Gasteropods,* the 

 * Troschel, Hand, der Zoologie. 



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