MUSEUM OF COMPARATIVE ZOOLOGY. 3G0 



of the first three abdominal segments slightly produced. Hind margin of 

 fourth abdominal segment in some examples has a median projection over 

 the telson, but in others this is reduced to the bold convexity of the whole 

 border (Figs. 24, 25). Telson entire. First antenna equal in length to the 

 distance from the eye to the fifth dorsal spine ; fiagellum composed of thir- 

 teen segments. Second antenna equal to distance from the eye to the sixth 

 dorsal spine; basal segment distinct; olfactory denticle prominent; fiagel- 

 lum composed of fourteen segments. Carpopodite of second pair of legs in the 

 male produced at the lower angle ; propodite not very large (but larger in the 

 male than in the female) with a slight projection at the lower angle ; a few 

 setae on the lower margin. Sixth and seventh pair of legs very lonf, about 

 equal to the distance between the first and ninth dorsal spines. Third pair 

 of caudal stylets very short ; a few seta3 on the hind margin of penultimate 

 segment, and one very slender seta at the tip of the terminal segment. 

 Length from front of head to end of telson, about 10 mm - 



Achacache, 11 fathoms, 12 specimens. 



Gulf of Puno, 10 specimens. 



Gulf of Desaguadero, 1 specimen. 



Chuquito, 40 fathoms, 1 specimen. 



The specimen from Chuquito is a female with eggs. It is more transpar- 

 ent than the others, the first two dorsal spines longer and curved forward as 

 in A. lucifugax. The epimera of the first four thoracic segments are also 

 longer in this specimen than those obtained from other localities. 



Allorchestes lucifugax, sp. nov. 



' Fig. 26. 



Allorchestes lucifugax, male (nat. s. 11: 



A longitudinal row of eleven spines along the median line of the back. 

 The first spine arises from the fore margin of the first thoracic segment ; the 



