386 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



lu Nos. 1 to 4 \ve fiud little variation from tbe brevicarpus form, wtiich we coiisitler as nearest 

 to tbe type of tbe species. From No. 5 to No. 15 tbe departure from this type is increasingly 

 evident, and in Nos. 12 to 15 we recognize the widest divergence in the varity lonyicarpus. 



No. 5 is an interesting case, siuce it combines the characters of both varieties. Tbe aural 

 spine is rather blunt and extends to one third the length of tbe second segment of the autenular-stalk. 

 The inferior basal spine is rather less than one-half the length of sqnamous spine ; upper basal spine 

 a rudimentary knob. The squamous spine has a well developed sqname; nearly equals length 

 of anteunal peduncle. The "finger" and "thumb" of small chela end in simple, sharply pointed 

 hooks. There is an inconspicuous tuft of set* on the dactyle. The carpus is long. (See Table If.) 



No. 8 is also an interesting variation. The antenna are intermediate in character, between 

 the extremes of the table, while the small chela is of the brevicarpus type. There is a rudimentary 

 autenual scale. The tips of the small chela are simple. There i-> no tuft, and the carpus is short. 



In No. 9, which is of the same sex, the same length, and from tbe same locality as No. 8, the 

 small chela has the characters of the variety lonyicarpus. Nos. 5 to 12, in tbe middle of the table, 

 show iu one way or another intermediate characters between the extremes, Nos. 1 to -1 arid Nos. 

 12 to 15. 



VI. MEASUREMENTS IN MILLIMETERS. 



TABLE n. 



[Locality: Nassau, N. P., Bahama Islands.] 



