31icrodeutopiis 589 



IGuathopod 1 in (S, »th joint with accessory tooth 

 at base of principal t>. M. anomalus . . . p. 591 

 Gnathopod 1 in S, ötli joint with accessory tooth 

 apart from principal • . . . 7. M. propinquns . . p. 592 



( Antenna 1, flagellum shorter than peduncle . . 8. M. megnae . . . . p. 592 

 \ Antenaa 1, flagellum longer than peduncle — 9. 



i Glnathopod 2 in (5 very slender and very setose 9. M. versiculatus . p. 593 

 9 < Gnathopod 2 in (5 not very slender and not very 



I setose 10. M. damnoniensis . p. 593 



1. M. ehelifer (Bäte) 1862 Stimpsonia chelifera, Bäte (& Westwood), Brit. sess. 

 Crust., V. 1 p. 285 f. | 1862 S. c, Bäte, Cat. Amphip. Brit. Mus., p. 162 t. 29 f. 9 | 1878 

 S.c, T. Stebbing in: Ann. nat. Hist., ser. 5 v.\ p. 34 t. 5 f. 2, 3 | 1888 S. c, Micro- 

 deutopus (part.), T. Stebbing in: Rep. Voy. Challenger, v. 29 p. 334 | 1893 Stimpsonella c, 

 A. Della Valle in: F. Fl. Neapel, v. 20 p. 424 t. 56 f. 42—45. 



Side-plate 1 with an acute front corner in d. Antennae 1 and 2 sub- 

 equal (Bäte: antenna 1 the shorter). Antenna 1, 2^ joint longer than 1^*, 

 3d YQYj Short, flagellum longer than peduncle, accessory flagellum 2-jointed. 

 Antenna 2, antepenultimate joint of peduncle very thick, penultimate very long, 

 at the base winged below so as to equal depth of preceding Joint, ultimate about 

 as long as penultimate or flagellum. Gnathopod 1 in d very large, the size 

 chiefly due tö the 5*^'* Joint, the distal tooth of which varies greatly in length, a 

 deep cavity separating it from a little setose tooth adjacent to base of the some- 

 what oblong 6*** Joint; 6^^ joint gently convex in front with undulating bind margin 

 and no conspicuous palm. Gnathopod 2 in d, 5*^ joint much longer than 6*^, 

 6*^ as broad as long, widening to the variable palm, which is defined by 

 a tooth sometimes large but capable of vanishing altogether, finger matching 

 palm. Gnathopod 1 in 9 , 6^*1 joint slightly larger than 5*^ about twice as 

 long as broad, palm defined by a palmar spine, overlapped by serrate finger. 

 Gnathopod 2 in o similar to gnathopod 1, but much smaller. Peraeopods 1 

 and 2, 4*^ and 5*^ joints much broader than 6*^. Peraeopods 3 — 5, 2*^ joint 

 narrow; peraeopod 5 much the lougest; in all peraeopods the 6*^ joint has 

 an apical group of setae. Uropod 3, peduncle short, stout. rami equal, little 

 longer than peduncle. Telson with a setule at the lateral notch on each 

 side of the rounded, unproduced apex. L. 8 — 9 mm. 



English Channel (South-Devon). 



2. M. armatus Chevreux 1886 & 87 M. a., Chevreux in : Bull. Soc. zool. France, 

 ».11 p. XLI: «.12 p.312 t. 5 f. 11, 12; textf. 6, 7 p. 296 | 1893 Stimpsonella armata, 

 A. Della Valle in: F. Fl. Neapel, u20 p.422 t. 4 f. 8; t.ll f.l3— 24. 



Yeiy slender; ventral surface of peraeon segments 2 — 4 (sometimes 

 others?) armed each with a spiniform tooth. Head without rostrum, lateral 

 lobes little prominent. Side-plate 1 in <5 little produced, in Q rhomboidal. 

 Eyes small, round, black. Antenna 1 rather shorter than the body, 2^ joint 

 longer than 1«*, 3*^ over 7« as long as 2^, flagellum longer than peduncle, 

 11-jointed, accessory flagellum very short, with 2 joints, 2* minute. Antenna 2 

 much the shorter, ultimate joint of peduncle as long as penultimate, slightly 

 longer than the 4-jointed flagellum. Gnathopod 1 in d, 2*^ joint very broad 

 except at the extremities, 5*^^ massive, bind margin finely crenulate distally 

 and produced to a sti'ong tooth, 6*^ much shorter and narrower, somewhat 

 oblong, with very iiTegularly crenate bind margin, finger long, slender. Gnatho- 

 pod 2 in d, 2^ Joint broad, fi-ont margin somewhat indentured and distally 

 produced, b^^ almost oblong, 6*** rather longer, oblong, palm only slightly oblique, 



