PUERTO RICAN COPEPODS — GONZALEZ AND BOWMAN 243 



the new family Calocalanidae. Only 2 genera remain in the Para- 

 calanidae, and they may be distinguished as follows : 



Acrocalantis Giesbrecht Paracalanus Boeck 



Re2 of P2-P4 with spinulose outer Outer margins smooth 



margins 

 Proximal part of outer margin of Proximal part nearly or more than 

 Re3 of P2-P4 less than twice as twice as long as distal part 



long as distal part 

 Female P5 absent Female P5 2-segmented, distal seg- 



ment with 2 unequal terminal 

 setae 



Two species of Acrocalanus occur in the Atlantic Ocean (Bowman, 

 1958), but both are oceanic species and are not found in the inshore 

 waters of Puerto Rico. The 3 species of Paracalanus that occurred 

 in our collections are considered below. 



Key to Females of Local Species of Paracalanus 



1. Very small species, usually less than 0.5 mm. long; rostral filaments thick 



and blunt; terminal setae of P5 short and stout crassirostris 



Larger species, usually more than 0.75 mm. long; rostral filaments filiform; 

 medial terminal seta of P5 long and slender 2 



2. Al longer than body; Bl of P3-P4 without surface spinules . . . aculeatus 

 Al shorter than body; Bl of P3-P4 with surface spinules parvus 



In our collections, P. crassirostris is one of the 2 most common 

 calanoids, especially in the bays. P. parvus is common, more con- 

 sistently on the inner shelf than in the bays. P. aculeatus rarely 

 occurs in inshore waters and may be characterized as an offshore 

 species. 



Paracalanus aculeatus Giesbrecht 



Figures 2a-e 

 Paracalanus aculeatus Giesbrecht, 1888, p. 332; 1892, pp. 164, 169-170, pi. 9, 

 figs. 20, 26, 30.— Dahl, 1894, pi. 21.— Cleve, 1900, pp. 78-80.— Farran, 1929, 

 p. 222.— Davis, 1950, p. 93 (table) .—Carvalho, 1952, pp. 142-143, pi. 1, 

 figs. 11-12.— Wickstead, 1956, pp. 8-9.— Grice, 1960a, p. 220.— Legar^, 

 1961, table 5.— Zoppi, 1961, table 4.— Breuer, 1962, p. 167.— Cervig6n, 1962, 

 p. 183.— Grice and Hart, 1962, p. 293.— Fish, 1962, pp. 10-11.— Bjornberg, 

 1963, pp. 25-26. 



Female. — Length 1.02-1.08 mm. Prosome : urosome = 3.5-3.8. 

 Head rather vaulted, rostral filaments filiform. Prosome without dor- 

 sal hmnp. Innermost caudal seta more than twice as long as caudal 

 ramus. Al longer than body. Third lobe of Bl of Mxp with 3 

 setae. P2-P4, Bl without surface spinules; Ili2 with prominent 

 spinules on posterior surface. Re2 of P4 with row of rather broad, 

 blunt, thin-walled spinules on posterior surface. Inner terminal 

 spine of P5 2.5-3.0 times as long as outer terminal spine, considerably 

 longer than distal segment. 



