252 Transactio7is of the Society. 



Eoyal Microscopical Society. His finding Chirocephalus, in the 

 first instance, was by no means the result of chance, but was 

 owing to long and patient search over a considerable area. When 

 it is understood that the time for search was restricted to the little 

 leisure enjoyed by a man leading a busy wprking life, I am sure 

 that the Fellows of this Society will appreciate his efforts at their 

 true value. 



The anatomy of Chiroceplicdus has been described in Baird's 

 Entomostraca, and has been more fully dealt with under Phyllopoda 

 in the Cambridge ]!^atural History. 



The series shown here commences with the ova immediately 

 after deposition. Baird's figure (vol. v, fig. 1) hardly does justice 

 to these. He describes the ovum as yellowish, spherical, and 

 enclosed in a thick hard envelope, beset all round with short set;:e. 



These setse more resemble short spines, and are surrounded hy 

 a delicate transparent membrane, which is readily seen in slide 

 No. 1. 



The ovum after a few days assumes a greenish colour, probably 

 owing to its becoming covered with vegetable growth, and by the 

 time it is mature the setae or spines are almost obliterated. In 

 about twelve days the hard outer case cracks, and the young larva 

 enclosed in a delicate transparent envelope begins to emerge. 

 This is seen in the second slide. Complete emergence is seen in 

 the third slide, the larva being still covered with the envelope, 

 in which it remains for a few hours. 



The envelope is thrown off, and the young larva is then in the 

 condition shown on the fourth slide. A rapid change takes place 

 in the next three or four hours. The abdomen lengthens consider- 

 ably, and the lateral eyes are just visible. This is seen on the 

 fifth slide. Slides 6 to 9 show the development of the larva at 

 intervals of 5, 10, 15, and 21 days. 



One of the most interesting features of these Phyllopoda 

 is the striking development of the second antenna in the male, 

 which are modified for clasping. In the Cambridge Natural 

 History this antenna is described as follows : — " In Chirocephalus 

 diaphanns the main branch of the antenna consists of two large 

 joints, the terminal joint being a strong claw, with a serrated 

 process at its base, while the proximal joint bears two appendages 

 on its inner side. One of these is a small subconical tubercle, the 

 second is more complicated, consisting of a main stem and five 

 outgrowths. The main stem is many-jointed and flexible, the 

 basal joint being larger than the other, and bearing on its outer 

 side a large triangular membranous appendage, and four soft 

 cylindrical appendages. Except during the act of copulation this 

 remarkable apparatus is coiled on the inner side of the antennary 

 claw." 



Sometimes during the narcotization of Chirocephahis by cocaine 



