PEREZ FARFANTE: DIAGNOSTIC CHARACTERS IN HEPOMADUS 



60 - 



55 



30 7- 



CD D 



OO * D D 



D 



D 



^^ 



* O 



J L 



D* 



J L 



J L 



o o * 



Group I * 

 Group 2 O 

 Group 3 n 



14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 



carapace length (mm) 



Figure 9. — Ratio of interval between last two rostral teeth (A) to interval between first two 

 teeth (B) plotted against carapace length in the three groups (see text) of Hepoinadus tener. 



* Bouvier, 1908, pi. 13, fig. 2. 



** A. Milne Edwards and Bouvier, 1909, pi. 1, fig. 3. 



Table 2. — Ratio of rostrum length to carapace length at 

 various carapace lengths (c.l.) in the three groups (see text) 

 of Hepamadus tener. 



one species. In the specimens of Group 1, the 

 ratio varies from 0.55 to 0.90 (Figure 10), 

 in those of Group 2, from 0.30 to 1.0, and 

 finally, in specimens of Group 3 the ratio varies 

 from 0.30 to 0.45, except for a single individual 



in which the ratio is 0.55. It thus seems as if 

 the specimens of Group 1 possess a longer 

 spine on the third pleonic tergum than those 

 of Group 3, but in specimens of Group 2 that 

 spine may be as long as, or even longer, than 

 in the specimens of Group 1, or as short as in 

 those of Group 3. 



The setation of the endite of the basis of the 

 second maxilla varies within the same limits 

 in the three groups, i.e., 0, or 2 to 4 strong and 



1 to 4 weak setae on the upper side; and 0, or 



2 to 5 strong and 1 to 4 weak setae on the 

 lower side. Inasmuch as setae are found in 

 many combinations and are lacking on the 

 lower side in a few of the specimens examined 

 by me, it seems highly probable that the absence 

 of setae from the upper side of the endite in the 

 specimen reported by Milne Edwards and 

 Bouvier (1909) may very well fall within the 

 range of individual variation within the species. 

 I have not seen this specimen which is neither 

 in the collection nor is it registered in the card 

 catalog of the Museum of Comparative Zoology 

 (Herbert W. Levi, pers. comm.). 



451 



