170 MARIE V. LEBOUR. 
ECHINODERMATA. 
Holothurian juvy. Rare in December and January. 
Ophiopluteus. Begins in March, very common towards the end of the 
month, dwindles in April and disappears in May. Occurs again in August 
and September, common in September. 
Echinopluteus. A few occurred once in the middle of November, 1915, 
begins in May, not common. Very common at intervals in July and 
August. 
Auricularia. Rare, January and February. 
Very young Echinoderm larvee in March. 
TUNICATA. 
Orkopleura dioica Fol. Common from February to May and from 
August to September, otherwise not very common and occurring at 
intervals. Commonest in early April and early August. 
Appendicularian indet. Rare in August till November, and in February. 
Fish eggs and young fish were occasionally present. 
A Survey of the Plankton in each month both from water samples and tow nets. 
1915. September (21st to 30th). 
Winds mainly 8. and 8.E. Weather fairly fine. Shows both groups 
of diatoms. Coscinodiscus species, Biddulphia mobiliensis and regia 
beginning, Rhizosolenia which is almost at the end of its season not 
common except R. Stolterfothii, which is still abundant. Skeletonema, 
Chetoceras constrictum and Asterionella common, Paralia fairly common. 
Very few Peridiniales except Prorocentrum micans which is near its 
maximum and Ceratium fusus. Of the other unicellular groups Laboea 
species occur in small numbers, Tintinnopsis ventricosa is abundant 
and Pontosphera Hualeyi occurs singly several times. 
Of the Coelenterates Phialidium hemisphericum and Obelia meduse 
with young Pleurobrachia are common, but no other species. Amongst 
the Annelids Autolytus longiferiens and rubropunctatus occur singly with 
eggs and a few larvee of various kinds are present. Sagiita is very common, 
Cyphonautes present but not abundant. 
Many copepods occur, Acartia, Calanus and Pseudccalanus are the 
commonest, also common are Centropages typicus and hamatus and 
Temora and Coryceus is common at the end of the month. Brachyura 
zoee and the larva of Hippolyte are common, Porcellana zoex and Podon 
intermedius are common in the middle of the month and dwindle or 
