Islands; Hawaii (2 collections) ; Matzatlan, Mex- 

 ico; Panama (Pacific) ; Tylosurus jmiictulatus, 

 Philippines (2 collections). 



Female. — Body form as in plate 4 and figure 

 157. The female of this species was redescribed by 

 Shiino (as L. comutus) in 1965 so no further dc- 

 scrii")tion is given here except as pertains to vari- 

 ation in the lateral cephalic processes. These proc- 

 esses, by which the females of this species can be 

 separated from the preceding species, show great 

 variation in development. However, little correla- 

 tion could be found witli host or locality regarding 

 this variation. Plate 4 illustrates several examples 

 of variation in tliis cliaracter. In a series of 52 

 specimens from as many collections the width of 

 the cephalon across the lateral processes was com- 

 pared with the length of the cephalon. Unlike 

 L. belanes, where the widtli of the cephalon at the 

 posterior corners is less than or occasionally 

 equal to the cephalon length, the width of the 

 cephalon of L. tylosurl at this point, because of 

 these processes, is significantly greater than the 

 cephalon length. A summai-y of the measurements 

 for the 52 collections is presented below. 



The average widths, expressed as percentage of 

 cephalon length to width, for four host species are 

 as follows : 



A. hians 66.7 (13 collections) 



S. anastomella 76.5 ( 7 collections) 



T.crocodilus 77.3 (28 collections) 



T.acus 75.9 ( 9 collections) 



The average widths, expressed as percentage 

 of cephalon length to width, by geographical area 

 are as follows : 



) 



Western Atlantic 73.4 (13 collections) 



Eastern Atlantic 73.0 ( 6 collections) 



Indian Ocean 79.4 ( 9 collections 



Central and western Pacific 74.5 (23 collection;,' 



Eastern Pacific 77.3 ( 6 collections> 



Male. — Body form as in figure 158 and plate 3. 

 Total length 2.4 mm. (single specimen from S. 

 anastomella — Japan). Cephalon wider than long 

 (0.82 by 0.68 mm.) and making up about one- 

 (juarter of the body length. Caudal rami armed 

 with four setae as indicated in figure 159. Append- 

 ages as in L. belones except for the following 

 subtle differences. Tip of leg 3 (fig. 160) with the 

 spine-bearing portion knoblike. End of leg 4 (figs. 

 161, 162) bifurcate (as in L. helones), each branch 

 with knoblike tip bearing short spines; indenta- 



COPEPODS AND NEEDLEFISHES 



tion between branches deeper than in L. helones 

 (compare figs. 155 and 156 with 160 and 161). 



Remarks. — L. tylosuri and L. helones are com- 

 mon on needlefishes. In the 146 collections of these 

 species tlie two species of copepods were never 

 found on the same host individual. The following 

 list shows the frequency of each copepod species 

 on each host species and demonstrates host speci- 

 ficity within each species of copepod (the numbers 

 refer to numbers of collections) : 



L. tylosuri clearly is common on Ahlennes hians, 

 Strongylura lekira, S. a/naMomelJa, and the sjiecies 

 of Tyloswi'us, whereas L. helones is predominant 

 on the other species of Strongylura. 



FAMILY LERNAEIDAE 



Two members of this family were collected, 

 Lemaea sp. and Lemaeenicus sp. Neither of these 

 is considered a specific parasite of needlefishes. 



Lemaea Sp. 



Figures 163, 164 



A single ovigerous female (6.9 nun. long) was 

 removed from the pit immediately behind the left 

 pectoral fin of a Xenentodon camcUa collected in 

 an unknown fresh-water locality in southeast Asia. 



Tlie cojiepod may l>e an undescribed sjjecies but 

 in view of the amount of variation whicli occure 

 within the species of this genus (see Ho, 1961) and 

 the lack of locality data, description on tlie basis 

 of a single specimen would be premature. Figures 

 of the whole animal (fig. 163) and the anchoring 

 apparatus (fig. 164) are provided. One of the 

 horns seems to be deformed in this sjjecimen. 



389 



