160 
BULLETIN OP THE BUREAU OF FISHERIES 
V.A. 
The females of Pinnotheres macvlatus 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 swimxning. The 
young of this species formed one of the most abimdant members of the plankton from 
July 6 to November 1, 1922 (see fig. 60). P. ostreum has similar habits but is not as 
common as P. maculatus. 
The imusual larvae of Polyonyx macrocheles occurred scatteringly from July 26 
to October 29, 1922. These peculiar zoeae differ from all other forms in the great 
length of the rostrum. On July 16, 1892, a sample of towings from Taimton River, 
Mass., was found to contain swarms of this species. Hardly anything else appeared. 
Faxon found the zoese swarming at the mouth of Massachusetts Bay in August, 1878. 
The adults are exceedingly rare. Agassiz found 
one adult at Newport under a stone, and Doctor 
Tennent collected one on Devil's Foot Island in 
a Chastopterus tube. G. Gray reports that 
several were found in Chaetopterus tubes at Woods 
Hole in 1922. In 1923 the zoeae 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 irroratiis appears first, followed closely by 
Neopanope texani sayi (fig. 62). In 1922 the first 
zoea 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. Figiu-es 60, 
61, and 62 show the breeding seasons of the most 
abundant species taken in 1922, while the scarcer 
forms appear on Figure 58. 
In 1922 another zoea, almost identical to 
that of C. irroratus, was first found on Septem- 
ber 8 and continued until October 31. This was imdoubtedly C. horealis, 
although the megalops were smaller than those of C. irroratus, a smaller species. 
Adult specimens of C. horealis taken at No Man's Land on August 31, 1923, con- 
tained ripe eggs. The first larvae appeared in Great Harbor on October 4; the last 
on October 28 (fig. 59). 
The following brachyuran larvee were taken at Woods Hole in 1922 and 1923. 
Pelia mutica (Gibbes). 
Neopanope texana sayi (Smith). 
Polyonyx macrocheles (Gibbes). 
Pinnotheres ostreum, Say. 
Pinnixa sayana, Stimpson. 
P. chaetopterana, Stimpson. 
T.s 
Fig. 60. — Occurrence of common grapsoid larvee 
in surface collections of 1922. , Pinnixa 
chxtopterana; — • — , Pinnotheres maculatus 
Cancer irroratus, Say. 
C. borealis, Stimpson. 
Ovalipes ocellatus (Herbst). 
Callinectes sapidus, Rathbun. 
Carcinides msenas (Linnaeus). 
Libinia emarginata, Leach. 
L. dubia, Milne-Edwards. 
Eurypanopeus depressus (Smith). 
Planes minutus (Linnaeus). 
Heterocrypta granulata (Gibbes). 
Pinnotheres maculatus, Say. 
Uca pugnax (Smith) . 
U. pugilator (Bosc). 
