160 BULLETIN OF THE BUREAU OF FISHERIES 
The females of Pinnotheres maculatus are commensal in Mytilus. The males 
swim freely about and were often taken during the breeding season but never after. 
Young males in all stages of development were frequently seen swimming. The 
young of this species formed one of the most abundant members of the plankton from 
July 6 to November 1, 1922 (see fig. 60). P. ostrewm has similar habits but is not as 
common as P. maculatus. 
The unusual larve of Polyonyx macrocheles occurred scatteringly from July 26 
to October 29, 1922. These peculiar zoéz differ from all other forms im the great 
length of the rostrum. On July 16, 1892, a sample of towings from Taunton River, 
Mass., was found to contain swarms of this species. Hardly anything else appeared. 
Faxon found the zoéx swarming at the mouth of Massachusetts Bay in August, 1878. 
The adults are exceedingly rare. Agassiz found 
Ss Sylore one adult at Newport under a stone, and Doctor 
Tennent collected one on Devil’s Foot Island in 
a Chetopterus tube. G. Gray reports that 
several were found in Chetopterus tubes at Woods 
Hole in 1922. In 1923 the zoéx were taken from 
July 20 until August 22 (see fig. 59). 
The various species of crabs have definite 
breeding seasons, which often overlap each other. 
Cancer irroratus appears first, followed closely by 
Neopanope texant say? (fig. 62). In 1922 the first 
zoéa, of Cancer was observed on May 10. None 
appeared during April of the present year (1923), 
although many females bearing late eggs were 
taken on April 10 in lobster pots. Figures 60, 
61, and 62 show the breeding seasons of the most 
abundant species taken in 1922, while the scarcer 
Fic. 60.—Occurrence of common grapsoid larve forms appear on Figure 58. 
et ca i min ste amen ec In 1922 another zoéa, almost identical to 
that of C. irroratus, was first found on Septem- 
ber 8 and continued until October 31. This was undoubtedly C. borealis, 
although the megalops were smaller than those of C. aroratus, a smaller speciés. 
Adult specimens of C-. borealis taken at No Man’s Land on August 31, 1923, con- 
tained ripe eggs. The first larve appeared in Great Harbor on October 4; the last 
on October 28 (fig. 59). 
The following brachyuran larve were taken at Woods Hole in 1922 and 1923. 
E 
Jule 
VA. 
Cancer irroratus, Say. Pelia mutica (Gibbes). 
C. borealis, Stimpson. Neopanope texana sayi (Smith). 
Ovalipes ocellatus (Herbst). Polyonyx macrocheles (Gibbes). 
Callinectes sapidus, Rathbun. Pinnotheres ostreum, Say. 
Carcinides menas (Linnzus). Pinnixa sayana, Stimpson. 
Libinia emarginata, Leach. P. chetopterana, Stimpson. 
L. dubia, Milne-Edwards. Pinnotheres maculatus, Say. 
Eurypanopeus depressus (Smith). Uca pugnax (Smith). 
Planes minutus (Linnzus). U. pugilator (Bosc). 
Heterocrypta granulata (Gibbes). 
