21 

 4096-413:^ 4145-64 



3. Metapeneus Dobsoni, Miers. Plate III., fig. 9, ^a-J. 



PenxuK Do!)TO,ii Miers, P.Z.S., 1S78. p. 302. pi. ivii. fig. 2: J. R. Henderson, Trans. Linn. Soc. (2) V. 1893, 

 p 449. 



Metapenseui Dobsoni, Nobili, Boll. Mus. Torino, 1003, No. 452, p. 3. 



In general characters this species resembles M. monoceroft, bnt exhibits the 

 following diagnostic points of difference: — 



The tomentum is less harsh, less abundant, and more patchy. 



The rostrnm, which has only 8 or 9 teeth, is usually a little longer, and it 

 has a well-marked double curve. The post-rostral crest fades away well in front 

 of the posterior border of the carapace ; and the anterior abdominal terga are 

 not, or only most obscurely, carinated. The post-auteiinular (antennal) spine is 

 not very strong and is not continued backwards as a strong ridge, so that the 

 post-antennular sulcus is not so deep. 



The iiuii^r antennular flagellum is the longer, exceeding its peduncle in 

 length. 



All the legs are shorter and more ciliated, and the chehie are ufiusually 

 weak. In the male the spine on the basis of the 3rd pair of chelipeds is a great 

 barb projecting considerably beyond the base of the merus, somewhat like that 

 of M. Joyneri. 



The last pair of thoracic legs do not nearly reach the middle of the anten- 

 nal scale : in the male, owing to a twist in the ischium, the large tooth (com- 

 pleting the notch) at the proximal end of the merus is turned forwards and 

 outwards; and anterior to this tooth there may be a second smaller tooth, but 

 no row of denticles. In tlie adult female the last pair of thoracic legs is gener- 

 ally represented by a coxa, to which is articulated a horny stump : this is the 

 case in 62 out of the 69 females in our collection ; but of the remaining 7, 5 

 have a normal leg — short and weak like that of the male, but without notch or 

 spine on merus — on one side, and 2 have a pair of normal legs. 



The andricum is much like that of M. ytionocero.i, but. ends in a pair of 

 simple spouts ; and where tlie spouts t:i,ke-o(f there are I papillae, or short fila- 

 ments — two anterior iud two posterior. 



