1.8a CEYLON PEARL OYSTER REPORT. 



opening is very wide, extending more than lndf-way round the body, and ending a 

 short distance below and behind the eyes. The siphon is comparatively short, 

 extending rather less than half-way to the umbrella margin. 



The Head is comparatively small, and the eyes but slightly prominent. 



The Arms are long and stout, on an average nearly four times as long as the body. 

 The umbrella is moderately developed ; it is narrowest between the two dorsal arms, 

 somewhat broader between the two ventral, and between the lateral arms about ecmal 

 to the length of the body. The suckers are of moderate size and closely packed ; the 

 first four are in a single series, the remainder in two series. 



The Surface is wrinkled by folds, probably due to contraction in spirit. It bears a 

 large number of prominent warts or tubercles ; on the back, these are for the most 

 part elongated antero-posteriorly, and the skin around them is thrown up into a 

 series of radiating folds ; four of these are arranged at the corners of a rhombus with 

 its long axis in the median line, a little distance behind the eyes, and about a dozen 

 others are distributed more or less irregularly on the posterior part of the back. 

 There are also a number of these elongated warts on the proximal portion of the 

 dorsal and dorso-lateral arms. There are two or three very minute warts above and 

 behind the eye. 



The Colour is a dull brownish-grey, paler below. At the base of the ventro-lateral 

 arm, about one-third of the distance between the eye and the edge of the umbrella, 

 is a large eye-like spot, about 13 millhns. in diameter, consisting of a pale centre 

 surrounded by a broad dark ring ; this in its turn is surrounded by a narrow pale 

 ring, again succeeded by a narrow dark one. 



Dimensions of Specimen No. 277 . 



Millims. 



Length, total 550 



End of body to eye 95 



Breadth of body 58 



head 47 



Eye to edge of umbrella, between dorsal arms . . 50 

 ,, ,, ,, ,, lateral ,, . . 80 



Length of first arm Right 316, Left 228 



,, second arm .... ,, 35G, ,, 316 



,, third arm ,, 330, ,, 330 



fourth arm .... ,, 356, 285 



Localities : Galle, caught by Professor Herdman in the lagoon. One specimen, 

 female [277]. 



Station XIX., Palk Bay. One specimen, sex (?) [201]. 



Station XVI., north of Periya Paar. One specimen, female [21G]. 



