166 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 112 



paratypes of thysanotus, USNM 64064. A slide, containing the parts 

 of a dissected female, labelled "Hemicyclops thysanotus — Paratype." 

 1 female from body surface, August 20, 1927, identified by S. F. Light, 

 USNM 90937, dissected. 



From Callianassa calif orniensis : C. 1 : 1 male syntype of calli- 

 anassae. 12 females, 6 males, 6 juveniles, paratypes of callianassae, 

 USNM 60433, all from gill chamber. Slide of a dissected female, 

 labeled "Hemicyclops callianassae — Paratype." 20 females, 11 males 

 from eggs, Wilson's thysanotus (figures 2a~b, d, f-l, and 3a-c, are 

 based on a female and figure la-d (labrum), e, g-p, and r on a male 

 of this lot). C.3 : 1 female from debris in bottle. 



From C. gigas: C.9: 12 females, 1 male from body surface, B. 

 Blanchard, June 1936, syntypes of pugettensis (discussion of type 

 locality in Gooding, 1958, p. 699). Slide of a dissected female labelled 

 "Hemicyclops pugettensis — Type," Illg's collection. Several speci- 

 mens from gill chamber and body surface, summers of 1956 and 1957, 

 e.g., 2 females, 2 males from 2 hosts, July 27, 1957; 6 females, 2 males 

 from 3 hosts, August 21, 1957; figure 2c, e, and h, was drawn from a 

 female and figure Id (labium),/, and g from a male, both of the first 

 lot. C.7b: Several specimens from gill chamber and body surface, 

 1955-58, e.g., 19 females, 9 males, 1 juvenile from 3 hosts, March 

 16, 1956; 54 females, 27 males, 9 juveniles from 5 hosts, February 3, 

 1958. C.8: 4 females, 1 juvenile from debris in bottle. 



From Upogebia pugettensis (a host of this copepod not previously 

 mentioned in the literature): C.2: several specimens between gill fila- 

 ments and in debris (one female was dissected). C.3: 9 females, 

 12 males, 10 juveniles from debris in bottle. C.4: 121 females, 88 

 males, 8 juveniles from debris in bottle; twenty specimens of each 

 sex have been deposited in the U.S. National Museum, No. 101368. 



Redescription of the female: Body 2.0 mm. in length (mean of 

 10 specimens, range 1.74-2.44 mm.) ; clearly divided into wide prosome 

 (0.9 mm.; 0.77-0.97 mm.) and narrower urosome. Color in life (re- 



Figure 1. — Hemicyclops thysanotus Wilson, male: a, Habitus, dorsal aspect, b, Right 

 antennule, dorsal (anterior) view, c, Right antenna, dorsal (posterior) view, d, Labrum 

 in dorsal, labium in ventral view, e, Right mandible, ventral (posterior) view. /, Right 

 paragnath, ventral (posterior) view, g, Right maxillule, dorsal (posterior) view, h, Left 

 maxilla, dorsal (anterior) view, with detail of base of setule-bearing seta from a different 

 aspect, i, Right maxilliped, ventral (posterior) view. /, Right first swimming leg with 

 coxal plate, ventral (anterior) view, k, Right second swimming leg with coxal plate, 

 ventral (anterior) view. /, Right third swimming leg with coxal plate, ventral (anterior) 

 view, m, Right fourth swimming leg with coxal plate, ventral (anterior) view, n, Right 

 fifth leg, ventral view, o, Ventral view of genital segment showing position of sixth legs. 

 p, Left sixth leg, lateral view, q, Spermatophore (somewhat swollen) expressed from 

 genital segment, r, Right caudal ramus, dorsal view. Scale A (fig. 2) applies to a: 

 D to b and i-m; E to c-d, g-h, and n-r; F to e; and G to f. 



