602 SjyO FLEAS FROM RHODE ISLAND— JUDD. 



This table is evidently inconsistent with tlie condition which obtains 

 in B. (/ainKirdii and other members of the family, for in this family the 

 males should be smaller than the females and have longer antenme. 



The following- is a table of other differences, which are sexual, if my 

 si)ecimens are males of B. loiu/iconiis ; but if they are simply sexual 

 differences, then this species exhibits by far the most exaggerated case 

 of sexual dimorphism known in the family. 



liijblis liiiujicnniis. 



FEMALE. 



Dorsum a continuous curve. 



r.yblis. tied' species. 



MALK. 



Dortiuni sliowing tootlied appearance just lieliind 

 the ccpliaion. 



Segmentation in both i>airs ot' antenme equally , Segmentation niiicli Ics.s distinct in inferior pair 



tlistinct. , of antenna'. 



I 



Ocular pigment " well detined. " ' Ocular pi;:ment absent. 



Posterior margins of first four cox;e rounded. Posterior margins (jf first four coxu' not so 



rounded, rather truncated. 



Segments ,") and of jileon have dorsal peaks. Segments 5 and of [deon have no peaks. 



The following is a table of differences which aftect parts not usually 

 subject to sexual dimorphism in this family: 



Byblis lonjicornis. i BifbUs. ik ir sjicciea. 



FEMALE. I .M.\LE. 



Length, 8 mm. Length, 8.5 mm. 



Superior antenme two-thirds length of body. Superior antenna' two-fifths length of Ixdy. 



Diameter of dorsal lens of eyes ecjual to diameter Diameter of dorsal lens of eyes two thirds diani- 

 of ventral lens. eter of ventral lens. 



Cephalon : 'Lower corner well marked and Cephalon : Lower corner not sharp, slightly 

 sharp;"* much longer than broad. ! longer than broad. 



Anterior periopoda : "Propodal. joint little longer I Anterior ]>enopoda: Twice as long as the carpal: 



than carpal;' dactylus equals propodos. I dactylus longer than propodos. 



No division between second and third last seg- A V-shaped division area between last three seg- 

 ments of pleon. ments of iileon. 



Last pleopodos : "Oppositeedges " of rami " finely Last pleopodos ; Ojiposite e(li;es of rami not ser- 



serrated; ' rami with no long hairs. rated; two rami br;ir on l)otli edges long hairs. 



Telson cleft onelifth its length. j Telson cleft three-fourths its length. 



' Sars' Crustacea of Norway, I, Pt. 9, p. 185. 

 •' Loc. cit. 



