UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 13, No. 1, pp. 1-20, pis. 1-2 April 14, 1914 



THE SCHIZOPODA OF THE SAN DIEGO REGION 



BY 

 CALVIN O. ESTEELY 



(Contribution from the Scripps Institution for Biological Research) 



This paper gives brief accounts of the Schizopoda contained in 

 the plankton collections of the Scripps Institution for Biological 

 Research made during the last five years with both surface and clos- 

 ing nets. 



The body of a schizopod is readily separable into a larger anterior 

 part, the cephalothorax (or the thorax) and a more slender posterior 

 portion, the abdomen. The thorax is covered by the carapace which 

 may be produced over the eyes into a rostrum ; this structure varies 

 considerably in shape and size within the group. Below the eyes 

 are found the antennules (also called the first or upper antennae) 

 which have two flagella attached to a 3-jointed peduncle. The 

 peduncle is of considerable taxonomic value. The antennae (second or 

 lower antennae) lie somewhat outside of and below the antennules 

 and have but one flagellar organ; the basal part of the antenna is 

 provided with the scale or squama which is of use in taxonomy. 



The mouth parts are behind and below the antennae, and consist 

 of the mandibles and maxillae ; following these there are eight pairs 

 of appendages which have received various names. Zimmer (1909, 

 p. 2) applies the term "cormopod" to the eight pairs of appendages 

 of the thorax that have both exopodite and endopodite. According 

 to Sars (1885) the first of these is the maxilliped, the others being the 

 legs. O'rtmann (1893, p. 5) used the term cormopod as Zimmer does, 

 the fourth to the eighth eormopods corresponding to the Avalking 

 legs of the Decapoda, the others being the counterparts of the "]\Iax- 

 illarf iisse. " On the other hand, Holt and Tattersall (1905, p. 101) 

 discard the term maxilliped and speak of the first thoracic appendage 



MAY • 1914 



