1913-] Miscellanea. 339 



The main bulk of the plankton in sample II consists of vege- 

 table debris and Copepoda, while the third sample contained 

 numerous Algae. 



By far the commonest Diatom present was a species of Nitz 

 schia: in addition there were present several different species of 

 Chaetoceras, among which I was able to recognize C. diversum, 

 C. peruviamim and C. lorenziannm. A single species of Rhizoso- 

 lenia, closely aUied to if not identical with R. setigera, was present, 

 but was extremely rare, only a very few individuals being found, 

 while a few examples of species of Ditonula and Melosira were also 

 seen, and a few filaments of a species of both Nostoe and Oscillaria. 



Dinoflagellates were present in considerable numbers, and of 

 these by far the commonest was Ceratium fusus, Ehr. Dr. Annan- 

 dale tells me that at the time the collections were made numerous 

 minute phosphorescent points were seen, and these were no doubt 

 due to these individuals. Among other forms were at least two 

 species of Peridinian's that I have been unable to identify. 



The Copepoda obtained belong to three species. 



I. Paracalanns crassirostris, Dahl. 



Paraca/an/is crassirostris, Dahl. " Die Copepoden Fauna des unteren 



Ainazonas ". Berichte der Naturforschenden Gesellschaft zu Freiburg. 



Zool. Abhand. n. sen. Vol. 8, p. 21, pi. i, figs. 27-28. Freiburg and 



Leipzig, 1894. 

 ? Paracalamis py^maeiis, T. Scott. " Entomostraca from the Gulf of 



Guinea". Trans. Linn. Soc. Zoology, series _', Vol. W, p. 27, pi. i, 



figs. 1-8. London, 1893. 

 Paracalamis crassirostris, Thompson and A. Scott. "The Copepoda". 



Ceylon Pearl Oyster Fisheries and Marine Biology, pt. I, p. 243. 



Royal Society, London, 1903. 



Numerous examples of this species (both cf and 9 )were present 

 in the collections. The form of the rostrum, the general propor- 

 tions of the body and abdomen and the structure of the 5th pair 

 of legs in the female exactly correspond with the figures given by 

 Dahl, and I have no doubt that the present specimens belong to 

 his species. 



Dahl only obtained examples of the female and as the male 

 differs in several details, I have given below a few notes on the 

 main points of its structure. 



cf . Total length 0-39 mm. 



Proportions of cephalothorax and abdomen 3:1. 



The head and rst thoracic segment are fused completely and 

 the 4th and 5th thoracic segments are partially so, but the line of 

 separation can in most cases be detected towards the ventral side. 



The abdomen consists of the usual five segments having with 

 the furcal rami the following proportions : — 6 : 7 : 5 : 4 : 7 : 7. 



The furcal rami are not quite twice as long as broad and have 

 convex inner borders. 



The 1st antennae, as in other members of the genus, have a 

 large basal portion consisting of several fused segments, and reach 

 as far as the posterior thoracic margin. 



