112 Mr. C. Spence Bate on Anomurous Crustacea. 



X. — Carcinohgical Gleanings. No. IV. 

 By C. Spence Bate, F.R.S. &c.* 



[Plates IX., X., XI.] 



The entrance to the English Channel appears to be the boun- 

 dary or extreme limit of two distinct faunas. We find species 

 that are decidedly arctic in their character represented by spe- 

 cimens that have a generally depauperized appearance, both as 

 to size and typical expression, while Mediterranean species are 

 represented without any large amount of variation in form or 

 dimensions of specimens. But my observations induce me to 

 believe that the southern forms, when taken on our shores, are 

 generally dredged from water of considerable depth ; whereas 

 those of the arctic types are as invariably taken in shallow water. 



The variations of depth and local habitats appear to us to 

 depend more upon the condition of food and its general supply 

 than upon other causes ; we therefore think that the geogra- 

 phical distribution of animals in limited regions can only be 

 worked out by a previous knowledge of the history of the ani- 

 mals, particularly in relation to their food, and even then can- 

 not be very reliable. 



Amongst the anomurous Crustacea I would wish to notice 

 the genus that Leach has named Munida in order to distin- 

 guish it from the genus Galathea ; but the points of distinction 

 are not sufficient to warrant so great a separation, and they 

 appear to me to be naturally but species of one genus. 



Three fine specimens I have recently taken on the shelly 

 ground off the Dudman, in about thirty fathoms of water. 

 The first specimen that was obtained differed from those pre- 

 viously known and described by having, instead of a long 

 central rostriform spine flanked by two shorter ones of analo- 

 gous construction, three equally important anteriorly porrected 

 spines — this in consequence of the two lateral spines being de- 

 veloped to a length corresponding with that of the central in 

 normal specimens ; whilst in another specimen the central 

 spine appears to be rather longer in proportion to the lateral 

 ones than that figured by either Leach or Prof. Bell, so that 

 the specimen bears a very close relationship to Galathea mono- 

 don of Milne-Edwards from the Brazils — a circumstance that 

 supports an opinion that I have elsewhere expressed, that 

 there is a very considerable resemblance between the Crustacea 

 of the South-American coast and that of the British seas. 



This species, Galathea hamffica {Munida Rondeletn^ Bell) , 

 is stated to be one of the rarest of our Crustacea, and is seldom 

 to be met with in our museums. Its habitat is most probably 



* Abstract, communicated by the author, from the Report of the Com- 

 mittee appointed to explore the Marine Fauna and Flora of the South 

 Coast of Devon and Cornwall. (Brit. Association Report for 1867, p. 275.) 



