4 P. T. CLEVE, NOTES ON SOME ATLANTIC PLANKTON- ORGANISMS. 



Female. Length of cephalothorax 0,88, of abdomen 0,25, of furca 0,05, of the longest 

 seta of the furca 0,4 millim. Breadth of cephalothorax 0,25 millim. 



Last segment of the thorax with two small finger-like processes. Its margin not 

 spinous. 



The genital-segment of abdomen three times longer than the second segment, which 

 is as long as the third one. The longest seta of the furca exceeds the abdomen in length. 

 All setffi of equal thickness. Furca nearly twice as long as broad. 



Rostral filamen t s present. 



Cephalothorax three times longer than broad. 



Fifth pair of feet: R. e very short, uniting with B. 2; its interiör margin denticulate. 



This fine species is most akin to A. verrucosa Thomps., but is easily distinguished 

 by the fifth pair of feet both of the male and the female. 



Habit at. The Azores, rare in August and September 1898. Temperature: 21,2 to 

 21,4. Salinity: 36,25 to 36,2» p. m. 



Corycseus longicaudis Dana. 

 Plate 1. Fig. 8—11. 



Male. Abdomen one-jointed, twice as long as the furca. Branehes of the furca 

 at least 7 times as long as broad. 



Dimensions'- total length 0,8, length of cephalothorax 0,5, of abdomen 0,3, of furca 

 0,i millim. 



The male of this species has not been described in Giesbrecht's »Systematik and. 

 Faunistik der Pelagischen Copepoden». It is common in the whole tropical Atlantic. 



Euchirella rost rata Claus. 

 Plate II. Fig. 1 — 12. 



Male. Head without crista, but with a subulate rostrum. Fifth foot six times as 

 long as its B. 2. Margin of its R. e. 2 not denticulate and of the R. e. 3 smooth. R. e. 

 of the posterior antennae twice as long as R. i. No triangulär scales on the inside of B. I 

 of the 4 th foot, 



Length of cephalothorax 2, of abdomen 0,5, of furca 0,08 millim. 



The male has not been described by Giesbrecht's in the Systematik und Faunistik der 

 Pelagischen Copepoden, but he mentions as quéstionable synonyme Euchceta Hessei Brady 

 (Chall. Rep. Vol. VIII pag. 63). A comparison af niy fig. of the fifth foot with the 

 drawing of Bra dy proves that Eueluvta Hessei is exactly the same as Euchirella rostrata. 



Some few specimens of the male were found together with several females in De- 

 cember 1898 oft" the Canaries. 



