﻿COPEPODS FROM LAKE ERH HAI, CHINA — HSIAO 173 



protopodite. Following the precedent established by Kiefer (1939) 

 in connection with the erection of the subgenus Ha'plodia'ptonms^ this 

 new subgenus might be diagnosed by a combination of the following 

 characters : 



(a) Fourth and fifth thoracic segments not fused together in bolh male and 

 female. 



(a) Spiny process on thirteenth joint of right first antenna of male very long, 

 longer than total length of thirteenth and fourteenth joints combined, and with 

 its distal end dilated and notched. 



(c) Antepenultimate joint of same antenna without spinous process but with 

 a thin hyaline lamella. 



(d) Endopodite of right fifth leg of male slightly indented on mesial side near 

 distal end. 



(e) Second joint of exopodite oi' same leg without any appendage or proc- 

 ess aside from lateral spine and terminal claw. 



(f) Large hyaline prominence on mesial side of first joint of this exopodite 

 instead of on protopodite. 



{g) Pincerlike structure on left fifth leg of male very small. 



The specific name is derived from the place on the shore of Lake Erh 

 Hai near which this form was collected. 



Types. — The type series consists of the female holotype, male allo- 

 type, and six male and female paratypes, U.S.N.M. Nos. 84544, 84542, 

 and 84543, respectively. 



Notes on life history. — Both males and females feed on blue-green 

 algae with occasional Cyclotella^ a common diatom in the lake. Most 

 of the females at this time carry a single bilobed egg sac, as long as 

 the abdominal section, containing four large ova. Frequently one or 

 two elongated fusiform spermatophores are attached on the genital 

 orifice with or without ovisacs present. 



Suborder Cyclopoida 



Family CYCLOPIDAE Dana-Sars 



Subfamily EucYCLOPlNAE Kiefer 



Genus EUCYCLOPS Claus 



EUCYCLOPS SERRULATUS EXTENSUS, new subspecies 



Figure 22 



This cyclopid, which occurs in Lake Erh Hai every month through- 

 out the year, was collected with a half-meter plankton net hauled from 

 east to west across the lake in 1945. It is very similar to G. O, Sars's 

 (1918) Leptocyclops agilis (Koch), to Gurney's (1933) Cyclops agilis 

 Koch, Sars, and to Kiefer's (1929) Eucy clops serrulatus (Fischer) 

 but shows certain minor differences from the descriptions given by 



