26 Records of the Indian Museum. (VoL. VII, 
Tomopaguropsis lanata, Alcock. 
Tomopaguropsis lanata, Alcock, 1905, p. 137, pl. xiii, fig. 4. 
A single male was obtained at St. 391 in a shell belonging 
to the genus Pleurotoma. 
Sympagurus arcuatus, Milne-Edwards and Bouvier, 
var. monstrosus, Alcock. 
Sympagurus arcuatus var. monstrosus, Alcock, 1905, p. 104, pl. x, 
fig. 5. 
Six specimens in Cancellaria cretacea, Smith, Pleurotoma sp. 
and in other gastropod molluscs, were taken at St. 391. The 
majority of the shells are encrusted by an anemone. 
Nematopagurus indicus, Alcock. 
Nematopagurus indicus Alcock, 1905, p. 109, pl. xii, fig. 4. 
Two specimens, a male and an ovigerous female obtained at 
St. 391, are referred to this species. 
They agree with Alcock’s description and with the type 
specimens in every particular except the eyes. These extend 
only to the end of the proximal third of the ultimate segment 
of the peduncle and are slightly shorter and very distinctly stouter 
than in the type. We have been unable to find any other dis- 
tinctions and we are convinced that the specimens are correctly 
referred to this species. 
Bouvier (1900, pp. 194, 198, and 1894, p. 69, pl. xi, figs. 2—6) 
has shown that in Sympagurus bicristatus, Milne-Edwards, and 
S. gracilipes, Milne-Edwards, there is considerable variation in 
the size of the eye. In the case of the former species Bouvier 
notes that in examples from comparatively shallow water the 
cornea is as a rule more dilated than in those from greater depths ; 
in S. gvacilipes, however, he is of the opinion that no such 
correlation exists. 
The present specimens were found in 237 fathoms and it is 
interesting to note that in these examples the eyes are more 
dilated than in the type specimens obtained at a depth of only 
102 fathoms. ‘The case, so far as the evidence goes, is therefore 
precisely the reverse of that found in S. bicristatus; but many 
instances of a parallel development in one direction or the other 
might be cited and it is no more difficult to believe that a shallow 
water species migrating to greater depths would find it more 
advantageous to increase its corneal area than that another 
species also migrating in a similar manner should in this respect, 
retrogress, finding that its other senses rendered ocular vision 
a secondary consideration. 
The specimens were found in shells of Nassaria coromandelica, 
Smith. 
