170 



no. Amphiaseus typhlops, G. 0. Sars, n. sp. 



(PI. CXI). 



Specific Characters. Female. Body very slender, sublinear in form, with 

 the 2 chief divisions nearly equal in length. Rostrum much attenuated, termin- 

 ating in an acute point. Caudal rami unusually prolonged, being fully twice as 

 long as they are broad, apical setae of moderate length and only slightly thick- 

 ened at the base. Eye wholly absent. Anterior antennae moderately elongated 

 and less attenuated than in most other species, 8-articulate, 4th joint not much 

 longer than 3rd, terminal part scarcely attaining half the length of the proximal. 

 Posterior antennae with the outer ramus about the length of the terminal 

 joint of the inner, middle joint very small and without any seta. Oral parts 

 normal. 1st pair of legs with the outer ramus about as long as the 1st joint of 

 the inner, middle joint with a well-developed seta inside, last joint somewhat 

 longer than the middle one, oblong oval in form, and armed with 4 slender spines 

 and a still more slender ciliated seta inside the spines; 1st joint of inner ramus 

 about the length of the other 2 combined, last joint very slender, linear, 3 times 

 as long as the 2nd, apical claw very long and evenly curved. Natatory legs with 

 the rami rather narrow and with a larger number of setae than in the 3 preceding 

 species, outer apical seta of inner ramus spiniform. Last pair of legs with the 

 distal joint very narrow, oblong in form, and carrying 6 rather slender marginal 

 setae; inner expansion of proximal joint narrow triangular, and extending to about 

 the middle of the distal joint, marginal setae 5 in number. Ovisacs comparatively 

 small, with a very limited number of ova. 



Male with the 2nd basal joint of 1st pair of legs produced inside at the 

 base to a small knob-like prominence, beyond which is a comb-like series of 4 

 blunt spines. Inner ramus of 2nd pair of legs rather slender, being fully as long 

 as the outer, and transformed in the usual manner, the distal joint carrying out- 

 side, at some distance from the tip, 2 spiniform appendages, the outer of which 

 is shorter and thicker than the inner. Last pair of legs, as usual, smaller than 

 in female, with the inner expansion of the proximal joint obtusely conical in form, 

 and carrying on the tip 2 spiniform setae of somewhat unequal length. 



Colour whitish. 



Length of adult female 0.93 mm. 



Remarks. This is a very distinct and easily recognizable species, being 

 especially characterised by the very slender linear form of the body, the narrowly 

 tapered rostrumy and the unusually prolonged caudal rami. Not the slightest 

 trace of an eye could be detected in the living animal. 



