158 
BULLETIN OF THE BUREAU OF FISHERIES 
near the bottom. Storms and strong currents may carry them to the upper strata, 
but the fact that they usually appear on only one or two days a year at the most 
indicates that their presence there is not normal. 
Certain other Macrura were found occasionally in summer surface collections. 
Emerita talpoida was first taken on July 22, 1922, and continued to appear in small 
numbers until September 1, when four appeared, the greatest number found on any 
one day. Invariably these larvae when placed in a watch glass would cast their 
shells and acquire the adult form within 24 hours. It was interesting to observe the 
• little creatures as they labored continuously to dig into the glass bottom of the dish. 
After a time they would drop exhausted but could be made to resume their activity 
by disturbing the surface of the water. 
Upogehia qffinis was taken twice in August, 1922. In English waters larvae of 
this genus are extremely numerous, but such is not the case at Woods Hole. The 
adults are not uncommon in this region, and in some years the larval forms may 
occur in greater numbers. In 1923 they were fairly abundant. The first specimen 
appeared on July 20 ; the last on October 25. The largest numbers were taken in 
early August. 
The transparent larvae of Callianassa stimpsoni Smith are frequently found in 
surface collections. Like Upogebia they are never found in abundance, although 
small numbers can usually be taken throughout July and August. In 1922 the first 
specimen appeared on July 16. After that scattered individuals were taken until the 
middle of August. The first larvae were observed on July 26, 1923. From August 
12 to 15 they were unusually numerous but soon declined again. The last specimen 
was taken on October 4. 
The young of the many species of Paguridae found in this region are always 
present in large numbers throughout the summer months. They are very similar 
to the larvae of various Caridea but may be distinguished by the cephalothorax, 
which is drawn out in two points on the posterio-ventral margin. M. T. Thompson 
(1903) made a careful study of this group and described the development of the 
interesting larvae. The early stages of the various species are almost identical, and 
in the case of the two most abundant forms — Pagurus longicarpus Say and P. 
annulipes (Stimpson) — it is impossible to distinguish them apart. Thompson 
found that P. longicarpus has the longest breeding season, extending from May 
until mid-September. Other species with eggs were found at different times 
during the summer. On April 8 of the present year (1923) two second-stage larvae 
appeared. This is unusually early and far antedates any records for the region. 
No other specimens occurred during the month. On May 8, 1922, a single larva 
was taken. After this scattering forms appeared until June 1, when they became 
very abundant. Together with all other macroplanktonic animals they decreased 
during the summer diatom maximum (see figs. 15 and 55). In September the 
swarms appeared for a short time but soon declined, the last one disappearing on 
November 9. The first Glaucothoe was seen on July 13. After this scattering 
forms appeared throughout the summer, although they never were as abundant 
as the zoese. Their distribution in 1923 is shown on Figure 53. 
