238 "TERRA NOVA" EXPEDITION. 



appear smaller than iu the young. Miss Richardson has noted similar differences in 

 the specimens she examined, and has rightly interpreted them as due to age. The 

 specimen I have figured agrees very well with the small specimen mentioned by 

 Hodgson from 60 fathoms, off Duke of York Island. There does not appear to be any 

 well-marked difference in the armature of the male and female. 



The terminal spines of the abdomen in this species are about one-tenth of the 

 length of the body. There is a well-marked pre-ocular spine on the lateral corners of 

 the head. 



The second antennae iu fully grown specimens are about equal to the length of the 

 body. The second joint of the peduncle is short, and bears a spine on the dorsal surface 

 of the anterior margin, a stronger and longer spine on the outer distal corner and a 

 smaller spine behind the latter. The third joint is less than half as long as the fourth 

 joint, and bears three small spines on the inner margin and three larger spines on the 

 outer margin, including the spine on the outer distal corner, which is the strongest and 

 largest of the series. The fourth joint has the outer distal corner produced into a 

 prominent spine. The fifth joint is one and a quarter times as long as the fourth joint, 

 and equal in length to the flagellum, which is composed of thirteen joints. 



The third thoracic limb has the outer corners of the fourth and fifth joints 

 produced into a spine. The fourth and fifth thoracic limbs have similar spines on the 

 third, fourth and fifth joints. The second joint of these limbs has at least one 

 prominent spine and generally two or three small spines on its outer surface. 



The sixth, seventh and eighth thoracic limbs have a few stout spines on the outer 

 face of the second joint, a strong spine on the hinder distal corner of the third joint, a 

 similar spine on the outer distal corner of the third joint, a double row of small spinules 

 on the front edges of the third, fourth and fifth joints, and a single row of about eight 

 small spines on the front edge of the sixth joint. 



The largest specimens reach a length of 43 mm., which is 6 mm. larger than the 

 specimens recorded by Hodgson. It is the most abundant species in the present 

 collection, and appears to have the centre of its distribution iu comparatively shallow 

 water, about 50 fathoms, at which depth it was most abundant. It is a matter of 

 some surprise that no specimens were collected by the " Discovery " ; and, indeed, only 

 one other expedition, the " Pourquoi Pas? " has met with this species. 



43. Antarcturus furcatus (Studer). PL VIII, figs. 1, 2. 



Arcturus furcatus, Studer, 1882, p. 57; Studer, 1884, p. 12, pi. I, figs. 3a-e ; Beddard, 



1886 (2), p. 85. 

 Antarcturus furcatus, zur Strassen, 1902, p. 686. 



Occurrence. — Station 220, off Cape Adare, mouth of Robertson's Bay, 45-50 

 fathoms, bottom fauna, one male, 29 mm., one juvenile, 24 mm. 



Station 314, 5 miles N. of Inaccessible Island, McMurdo Sound, 222-241 

 fathoms, bottom fauna, twenty specimens, largest female 40 mm., largest male 32 mm. 



