74 CRUSTACEANS OF THE 



three fourth the length of the cephalothorax. The outer 

 margin of the extraorbital tooth makes a right angle 

 with the upper margin of the orbits. The epibranchial 

 tooth or spine, directed straightly forward or slightly in- 

 ward, is, as in Parath. spinigera, widely distant from 

 the external orbital angle, the distance between the latter 

 and the tip of the epibranchial spine measuring about 

 one fourth the whole length of the lateral margin. The 

 base of the epibranchial tooth is about as far distant from 

 the outer angle of the orbits as the epistome is broad, 

 but in the type of von Martens the epistome is somewhat 

 broader than that distance. 



The epibranchial spine is strong, acute and sa- 

 lient, has a black point and is bounded anteriorly by 

 a deep notch. The slightly sinuous outer margin of the 

 extraorbital tooth makes with that notch an obtuse 

 rounded angle, but in the type described by von Mar- 

 tens this angle is less distinctly marked on one side, 

 faintly so on the other, the margin curving more regu- 

 larly towards the base of the tooth. The posterior margin 

 of the cephalothorax which is a little concave is, in the 

 adult, almost twice as broad as the free border of the 

 front, in the younger specimens somewhat shorter. 



The small orbits (Fig. 4«) are almost transverse, they 

 are once and a half as broad as high and their width 

 measures two thirds of that of the frontal margin. The outer 

 margin of the extraorbital teeth, the upper and the lower 

 margin of the orbits and the free border of the front are 

 smooth, entire. The somewhat sinuous infraorbital 

 margin has no hiatus near the outer angle and the 

 obtuse inner angle is small, little prominent: the inter- 

 space between this angle and the front is wide. According 

 to Hilgendorf the cornea of the eye-peduncles should be 

 slightly larger and the distance between the free border 

 of the front and the posterior margin of the epistome 

 somewhat shorter than in the Berlin type: in the adult 

 specimens this distance is half as long as the free border 



Notes from the Leytlen IMuweiim, Vol. XXI. 



