394 CEYLON PEARL OYSTER REPORT. 



CYCLOMETOPA. 



Carpilodes tristis, Dana, 1852 A. 3, p. 82. 



Locality : Galle, lagoon, three specimens (one adult c?, two young d"). 

 Description : C.l. of adult male = lO'O. 



Carpilodes pediger, Alcock, 1898 A.3, p. 83 : A. Invest., pi. xxxvi., fig. 4, ?. 



Localities : Off Mutwal Island, two specimens (one adult d" = a, one young d' = b) ; 

 west of Periya Paar, 17 to 24 fathoms, one specimen (adult ? = c) ; pearl hanks, Gulf 

 of Manaar, three specimens (adult 6 = </, ovigerous ? = f, young ? e). 



Description : C.l. of ovigerous female = 5 - 25. 



The third of the four anterolateral teeth of the carapace may be continuous with 

 the lobe 4L of Dana's nomenclature as in (/>), it may he separated therefrom by a 

 faint groove as in (a), (d), and (e), or by a more evident groove, agreeing with 

 AlGOCK's figure, as in (/). 



Carpilodes cariosus, Alcock, 1898 A.3, p. 86 ; A.Invest., pi. xxxvi., fig. 7, ?. 



Localities : Muttuvaratu Paar, 6 to 9 fathoms, one specimen (adult 6 = a) ; Gidf 

 of Manaar, three specimens (young d" = b, two adult = c, d) ; Jokkenpiddi Paar, 

 one specimen (adult ? = e). 



Description: C.l. of an adult female = 4"50. 



There is variation in lobulation of carapace. The lobe 3M (Dana's nomenclature) 

 is entire in all except the young male (d), where a groove separates the narrow 

 anterior limb from the posterior broad part. Lobe 2M is completely divided by a 

 longitudinal groove in all except the adult female (b), in which the groove is 

 incomplete posteriorly. The outer division of 2M is entire in adult females (b) and 

 (e) ; its inner border is notched in adult male (a) on both right and left sides of the 

 animal ; in adult female (c) its inner border is notched on the lobe of the right side of 

 the animal, while on the lobe of the left side there is an indication of a transverse 

 groove; finally, in young male (d) a distinct transverse groove divides the lobe of 

 each side. Lobe 5L is entire in all except adult male (), in which it is divided 

 obliquely. Lobes 2R, 1R-, and S are fused in adult male (a) and adult females (b, c) ; 

 in young male (d) and in adult female (e) there is an indication of their separation by 

 grooves. Variation is not always bilaterally symmetrical. The degree of sub-division 

 of the lobules is the most apparent difference between the present species and 

 C monticulosus. The variations above noted are within the limits allowed to the 

 species by Alcock. 



Atergatis mtegerrhnus (Lamarck), 1818 A.3, p. 95. 

 Locality : Galle, lagoon, one specimen (very small young). 



