DECAPODA. 3 



little shorter, and their terminal segment is hardly twice the length of the preceding ; 

 the carpus of the first legs is a little shorter than the hand. 



Remarks. This species agrees with the type of the genus Chorismus (C. tubercu- 

 latus, Sp. Bate.) in the characters given in my recently published synopsis of the 

 Hippolytidse ('Ann. Mag. Nat. Hist.,' xvii., 1906, p. 30), and further in having no 

 supra-orbital spines, in the mandible-palp being composed of three segments,* the gills 

 seven in number on each side, and the last three pairs of legs without epipods. It 

 differs in having eleven or twelve segments in the carpus of the second legs 

 while C. tuberculatus has only nine, in having an exopod on the third maxilliped, and 

 in the fact that the first segment of the mandibular palp is not shorter than the second. 



Occurrences. January 22, 1902. 500 fathoms, 1 $ . 



W.Q., February 28, 1902. Less than 20 fathoms, 1 $, 1 9 . 

 W.Q., January 10, 1903. 130 fathoms, 2 9. 

 W.Q., May 14, 1903. 127 fathoms, 1<J,1?. 

 W.Q., June 18, 1903. 130 fathoms, 2?. 



Fragments of this species were taken from the stomachs of seals on several 

 occasions. 



FAMILY CKANGONIM. 



CEANGONf ANTARCTICUS. 



C. antarcticus Pfeffer, Jahrb. Hamburg. Wiss. Anst. iv. (1887), p. 45, pi. L, figs. 1-21 ; Coutiere, C. R. 

 Acad. Sci. Paris, cxxx. (1900), p. 1640 ; and Bull. Mus. Paris, vi. (1900), p. 240. 



Description of females (not ovigerous). Total length, 37 ' 5-77 mm. General 

 form slender. Surface of the carapace very uneven, with strongly marked ridges and 

 hollows ; in particular, a more or less sharply defined ridge runs backwards from the 

 median dorsal spine for a distance equal to one-half the length of the carapace. The 

 ridge running backwards from the antennal spine is continuous with that running 

 forwards from the hepatic spine. Eostrum long, slender, compressed and acute, in one 

 case nearly one and a half times as long as the eye-stalks. Abdomen long and slender, 

 sixth somite generally more than one-sixth of total length of body. A pair of slender 

 acute spines on hind margin of fifth somite dorso-laterally. Sixth somite with a strongly- 

 marked double dorsal keel. Telson rounded at the tip, with a median spiniform point. 

 Antennular peduncle slender, the distal end of first segment narrower than one-half 

 the greatest diameter of the eye ; outer lobe of first segment nearly flat, broadly ovate, 

 produced anteriorly into a rather feeble spiniform point which does not reach distal 



* Spence Bate defines the genus Chorismus as having a " biarticulate synaphipod " (' Challenger Eep.' 

 Macrura, p. 616), but lie elsewhere correctly states that there are three segments (t.c. pp. 577 and 618). 



t Recent reforms in nomenclature having rendered most of the well-known generic names of Crustacea 

 unintelligible without an explanatory footnote, it is necessary to state that I use the name Crangon for the genus 

 of which the common shrimp is the type. 



