76 



PROCEEDINOB OP THE VATIO^AL MV8EVM. vol. xxxvi. 



Fig. 45. — Synalpheus heuricki angus- 

 tipes. k, large chela ; a"', s.mall 

 cheliped of first pair. 



In the third pair the proportions are : Meropodite 2.5 ; carpus 1 ; 

 propodite 1.55 (male) ; and 2.25, 1, 1.4 (female), by the shortening of 

 the meropodite and the propodite. In both cases the meropodite is 

 about 4 times as long as wide ; the dactyl is small, tapering distally, 

 with two slightly divergent hooks, the ventral the stronger and a little 

 the shorter. 



The height of the telson in the male is 1.6 times its base, 3.7 times 

 its posterior margin; in the female the height equals the base, and is 



4.5 times the posterior margin; in 

 both cases the spines of the supe- 

 rior face are ver^^ strong, and are 

 larger than the inner spines of the 

 posterior margin; between the lat- 

 ter are four plumose hairs and two 

 groups of four simple divergent 

 hairs; the external uropod generally 

 bears four teeth on its free margin, 

 and in addition a movable spine; 

 in the males the teeth may be three or two in number. 

 The eggs are of large size and give rise to mysis larvae. 

 Named for Dr. Francis H. Herrick, of Adelbert College. 

 This species, like the preceding, shows several variations. Among 

 the very typical specimens from Fish Hawh Station No. 7106 I find 

 a female who.se small chela is aberrant. In the females of S. hemcki 

 the meropodite and the sum of the carpus and the chela are in the pro- 

 portion of 0.74; in the specimen cited this portion is 0.71, and the 

 meropodite is more slender; the width is not, in fact, greater than 

 that of the palm, which latter is less 

 swollen at the base, its margins being 

 parallel along its Avhole length, the pro- 

 portions being T. L. : H.— 3 instead of 

 2.6 to 2.8; the carpus is no more than 

 0.65 of the entire chela, and it is as 

 wide as the palm at its distal end. In 

 all its other characters this female 

 (form angiist'tpcs) is a true herrieki; in 

 its small chela it approaches S. hrooh's't. 

 Six females from the same station 

 show some differences in the same di- 

 rection, but still more accentuated and not exactly comparable. The 

 palm and carpus of the small cheliped are very typical, the latter 

 measuring nearly O.S of the total chela, as in the male of S. herrieki, 

 and the palm beiug sAvollen at its base; the meropodite measures 0.77 

 of the carpus and chela together, which is also a character of the male 

 of S. herrieki (proportion 0.79), but it is 4 times as long as wide (in- 



FiG. 46. — Synalpheus herricki 



DIMIDIATUS. A', large CHELA ; 



A-', small cheliped of first 



PAIR. 



