38 Memoirs of the Indian Museum. [Voi.. Ill, 



capitular valves are represented as well as some of the peduncular plates. The young 

 hermaphrodite can thus be readily distinguished from the male, which only possesses 

 terga, scuta, the carina and rostrum. Figure 3 is from a section through a similar 

 specimen, showing the stomach {al.c), testes (/.), ventral nerve cord and the sensory 

 hairs on the outer surface of the capitulum {h.). The letters r.d. indicate the rostral 

 duct — the main blood or lymph channel from the prosoma to the peduncle, which is 

 again shown in pi. V, fig. 5, from a transverse section through the peduncle of a 

 specimen of similar size. 



Development of the testes in. the hermaphrodite. — The testes can be clearly distin- 

 guished in sections of the pupa as two small syncytial bodies lying at the sides of the 

 stomach. Plate iv, fig. 3, represents a transverse section through the prosoma of 

 an adult measuring 2-5 mm., in which t. indicates the testes. It will be seen 

 that they lie somewhat on the ventral side of the stomach. Each testis is clothed by 

 a fine membrane. There are no cell outHnes in their protoplasm. The nuclei contain 

 either one or two nucleoli and numerous minute chromatin granules. 



(ii) The Male. 



(I) The Pupa. 



I was sufficiently fortunate to obtain a specimen of a male pupa in the same 

 stage as the hermaphrodite figured in pi. iv, fig. i ; that is, in the course of the first 

 ecdysis after fixation. Plate iv, fig. 4, is taken from this specimen. On comparing 

 it with the hermaphrodite it will be observed to be much shorter in comparison to 

 its height, and the peduncular region is proportionately greater in comparison with 

 the capitular region.^ It measures 75 mm. in length. 



The stomach is not clearly visible, as it is overlaid by the left testis {t.). The 

 testes are, even in this early stage, much larger than in the hermaphrodite. The 

 mouth is open, but there is as yet no anus, the intestine being closed posteriorly. 

 The stomach contains matter which is apparently excretory. The condition of the 

 valves in this stage is shown in pi. iv, fig. 5. 



(2) The young Adult. 

 Plate iv, fig. 6, represents a later stage, after the completion of the ecdysis. 

 The only remaining portion of the larval integument is to be seen at the base of the 

 antennae. The capitulum has become extended on the peduncle into the adult 

 attitude. 



^ In connection with the views of Geoffrey Smith (11, p. 37) as to the nature of the parasitic males, 

 it is important to note that the male differs from the hermaphrodite before fixation (compare the pro- 

 portional measurements of the cyprid shell in the male with those of the hermaphrodite). Mai en ess is 

 therefore not the result of the position of attachment. 



It is hardly necessary to bring forward this proof, since in S. squamuliferum hermaphrodites occur 

 attached to all parts of other hermaphrodites, including the margin of the palliai aperture. That is to 

 say, they occur in that position which Smith considers to be the cause of the non-development of the 

 hermaphrodite character in the " males." 



