new Crustacea from Devon and Cornwall. 298 



This genus partakes of the characters of the two genera 

 Asterocheres and Scottocheres, but differs from both a3 

 described above. 



Mesocheres anglicus, sp. n. 



Cephalothorax of the female ovate, moderately robust, 

 widest in the middle, the width being equal to fully half the 

 length ; first segment about one and a half times longer than 

 the other segments combined : abdomen narrow and 'elon- 

 gated, as in Scottocheres longifurca, Giesb., and composed of 

 three segments, the first rather longer than the second and 



• - • TIT 



third together ; it is widest at the proximal end and produced 

 on each side into a hook-like process, as in the Scottocheres 

 referred to ; the anal segment is the smallest of the three, 

 being only a little more than half the length of the preceding 

 one. The.furcal joints are long and slender and about four 

 times as long as the last segment of the abdomen ; the outer 

 edge of each joint is fringed with minute bristles, and the 

 principal apical seta? are only moderately elongated. Length 

 about '65 mm. (^ of an inch). 



Antennules composed of twenty-one joints and somewhat 

 similar in structure to those of Asterocheres Boechi; a mode- 

 rately stout sensory filament springs from the end of the 

 eighteenth joint. Antennas three-jointed, the first joint longer 

 than the next two together, the third small and furnished 

 with one long and two short apical setae ; outer ramus small, 

 uniarticulate, with one or two slender apical seta?. 



First maxillipeds short, armed with elongated, stout, 

 strongly curved terminal claws ; a moderately long spiniform 

 seta springs from near the base of the claw. Second max- 

 illipeds long, slender, and similar to the same appendages in 

 Asterocheres Boechi. 



First four pairs of swimming-feet somewhat similar to 

 those of the same species, but the armature differs to some 

 extent, and especially that of the fourth pair ; in this pair 

 the spines on the outer margin and apex of the outer branches 

 are large and broadly dagger-shaped, and they are all, with 

 the exception of the inner terminal spine, finely serrated on 

 both edges, but the inner terminal spine is only serrated on 

 the outer edge ; the first and second joints are also provided 

 with a plumose seta on the inner margin, while the last joint 

 bears four plumose setaa on the inner margin in addition to 

 the four large spines on the outer margin and apex. The 

 first joint of the inner branches bears one seta and the second 

 and third joints two setae on the inner margin ; a similar seta 



