164 MR T. V. HODGSON ON THE 



are subequal in length, and bent on each other to form a loop which is so character- 

 istic of the genus Colossendeis. Each joint is furnished with four rows of non-denticu- 

 late spines, though on the terminal joint these spines are less regularly arranged, and 

 a fifth row may be distinguished. The spines vary a good deal in form and size ; the 

 larger ones are trenchant blades, bent rather close against the surface from which they 

 spring. The terminal claw is long and slender. These spines, as well as the terminal 

 claw, are much worn in all the specimens available, though of course to a varying 

 extent, and I would not assert that I had seen a perfect specimen. It does not appear 

 to me improbable that they should prove to terminate in a flattened blade with a 

 denticulate margin. 



The Leg extends to a length of about 83 mm. They differ in length, but without 

 measurement the difference is hardly noticeable. The fifth leg is the smallest, the 

 first comes next, and the fourth is intermediate between the third and fifth ; the second 

 and third are the largest and subequal. Of the three coxse, which are short, the first 

 is the shortest, and the second the longest, the differences being small. The first is 

 marked dorsally and ventrally by a faint groove passing along the greater part of the 

 joint, and rendered more conspicuous by a change of colour. Its distal extremity 

 is marked by a minute spine. The other coxse exhibit distinctly the " lateral line," 

 which is continued to the extremity of the limb. The proportions of the other joints 

 and claw are as 18, 19, 20'5, 8'5, 7, 5'5. There is a certain amount of variation, but it 

 is confined to narrow limits. Except for the spinous distal fringes, the limbs are 

 perfectly smooth. The distal fringe of the femur consists of one mid-dorsal spine and 

 two lateral ; these are quite small and inconspicuous ; that of the first tibia is generally 

 deficient ; those of the second tibia and tarsus comprise four long spines, each pair being 

 situated ventro-laterally ; a mid-ventral spine occurs occasionally. A pair of long 

 spines occurs ventrally on the propodus, one on each side of the claw. 



The Genital apertures occur on the second coxa of all the legs ; those of the male 

 are small and distal, those of the female are larger and median. 



Several specimens of this fine species were taken on various dates in Scotia Bay, 

 South Orkneys, in 9 or 1 fathoms. Two are quite immature, but show no traces of seg- 

 mentation, and in all particulars, except the non-development of the genital apertures, 

 resemble the mature specimens. Two specimens in the collection were marked as 

 bearing ova, but examination shows that these "ova" were bunches of contracted 

 hydroid polyps, and were held by the mandibles, but close against the ovigers. 



Colossendeis orcadense (Plate II.. fig. 3). 



Specific Characters. Body well built, with lateral processes widely separated. 

 Proboscis considerably longer than the trunk, and enlarged from near the middle 



onwards. 



Palps ten-jointed ; proportions of last three joints 1'8, 2'5, 2'5. 

 Ovigers ten-jointed, the last four joints with five rows of denticulate spines. 



(ROY. soc. EDIN. TRANS., VOL. XLVI., 184.) 



