SEA-FISHEKIES LABORATORY. 141 



becomes dry at low-water, and was obtained by means of 

 a "mussel rake," it was from this sample that the first 

 specimens were obtained, other samples sent later on in 

 the year also contained numbers of specimens. 



The specimens differ a little from the figures given by 

 Dr. Brady in his " monograph," especially in the length of 

 the basal joint of the first pair of swimming feet and also 

 in the shape of the fifth pair of feet of the female. 



Mesochra macintoshi, T. and A. Scott. 



[T. & A. Scott, An. & Mag. Nat. Hist., Ser. 6, Vol. 

 XV., p. 53, 1895.] 



A number of specimens of this species were obtained 

 from the shelly material dredged 1 mile off Spanish Head, 

 Isle of Man, from a depth of 16 fathoms. The slender 

 appearance of the species along with the structure and 

 armature of its various appendages, enable it to be readily 

 distinguished from the other members of the genus. 



Tetragoniceps trispinosus, n. sp. PI. II., figs. 24 and 

 25; III., figs. 1—6. 



Description of the Species. — Female. Length ' 5 millim. 

 (-sVth of an inch). Body elongate cylindrical, tapering 

 gently towards the posterior end, rostrum small and tri- 

 angular in shape. Antennules long and slender, six-jointed 

 and sparingly setiferous, the basal joint is considerably 

 longer than any of the others, fifth joint very small, about 

 half the length of the fourth ; the proportional lengths of 

 the joints are as shown by the following formula : — 

 28 . 13 . 14 . 8 . 4 . 16 

 1 2 3 4 5 6 



Antennae of moderate length and three-jointed, secondary 

 branch small and rudimentary, consisting of a single seta 

 attached to the lower margin of the second joint of the 

 primary branch at a distance of about one-third from the 

 base. Posterior foot-jaws small, with a strong curved 



