34 T. V. HODGSON. 



endopodite has a broad base, a straight inner margin, the greater part of which is 

 covered with fine setse. The inner margin tapers to a rounded apex, which is provided 

 with long plumose setse. The exopodite is a little longer, much more delicate, ovoid 

 in shape, fringed distally with long plumose setse. Where the exo- and endopodites 

 do not overlap the endopodite is very stoutly built. 



The second pair, the endopodite, is similar to that of the first, but quite without 

 any thickening ; the exopodite is very much smaller, ovoid, and the plumose setse occur 

 throughout the outer margin as well as distally. The appendix masculina is a narrow 

 structure of almost uniform diameter ; it is slightly curved* and enlarged near the 

 distal end. On the inner side of this enlargement and on the outer side of the 

 rounded extremity are series of very minute, backwardly-directed spines ; it is longer 

 than the endopodite. The third pleopod is like the second, but the inner margin of 

 the endopodite is slightly strengthened. 



The fourth pair has the exo- and endopodites subequal in size, heart-shaped, with 

 a shallow notch near the apex ; they are thicker and more fleshy than the preceding ; 

 they carry no setse. Both endo- and exopodites have an oblique fold in passing from 

 the antero-exterior margin towards the postero-lateral margin. The fifth pleopod is 

 rather larger than the preceding. The endopodite is more irregularly cordate and has 

 an oblique fold. The exopodite is larger and two-jointed, the second joint being about 

 one-fifth the length of the whole and terminates in a blunt but thickened point. 

 Another similar thickening occurs about the middle of its inner border and close to 

 it, and on the main joint is a further thickened knob. A ridge runs from this along 

 the inner border of the first joint for some distance and passes straight on inside a 

 lobe of the exopodite. 



A rather large number of specimens were taken at Cape Adare on February 24, 

 1904, from the root of a large laminarian Lessonia grandifolia, taken in 17 fms. 



ANTARCTURUS. 



The genus Arcturus was established by Latreille in 1804, and since that time it 

 has received a very large number of species, chiefly from the Southern Seas. Now, 

 however, the genus is to be broken up. Dr. zur Strassen has begun the operation and 

 separates the northern species which contain the type, from the tropical and southern 

 forms on the ground that in the type species the mouth parts are concealed from a 

 lateral view, and that the dactyli of the anterior pereiopoda are comparatively very 

 small. In the southern species the mouth parts are distinctly visible from a lateral 

 aspect, and the dactyli of the anterior pereiopoda are large. For these the genus 

 Antarcturus is instituted, and this contains the greater number of species. It is 

 probable, however, that it is only a temporary delay in the further breaking up of the 

 original genus, and if this alteration is to be carried on, minor characters, such as the 



