MOLLTJSCA. 85 



Cryptoplax striata, gimnii, rostrata, Adams, Genera, vol. i. p. 484^ 

 Angus, Proc. Zool. Soc. 1867, pp, 224, 325. 



Hab. Eaines Island, Torres Straits {Beeve, for C rostratus and 

 C. striatum), Port Lincoln \J. B. Harvey), Newcastle {Br. Bieffen- 

 hacli), Port Jackson {Goppinger, Richardson, Juices, King)- — all in 

 Brit. Mus. ; Flinders Island {J. MilUgan) ; Tasmania (Eeeve, 

 G. gunnii) ; Tasmania {Macgiltivray and Gunn, in Brit. Mus.). 



The variety gunnii, from South Australia and Tasmania, may be 

 recognized by the valves being narrower, with the exception of the 

 first two. This form also appears to attain a- larger size than speci- 

 mens from New South "Wales and other localities further north. A 

 specimen in spirit, from the mouth of the river Tamar, Tasmania, 

 presented to the British Museum by J. Macgillivray, exceeds four 

 inches in length. The mantle of the southern form also appears to 

 be rather less densely covered with the, minute conical spines. The 

 number of gills on each side varies with age, and even in individual 

 specimens : I have found 30 or 31 on each side in specimens of 

 equal size from both regions — that is, north and south ; and in the 

 largest specimen before referred to there are 37 on the right side 

 and 34 on the left, and there is no appearance of any having been 

 removed. The plates of insertion offer no distinctions, each having 

 three slits in the front valve and none in the rest, as is the case in 

 all Ghitonelli. The colour both of the valves and mantle seems to 

 agree very closely iii all the varieties. The C. rostratus of Eeeve 

 I cannot in any way distinguish from the shells figured by him as 

 Lamarck's 0. striatus, and the same observation also applies to his 

 notion of Quoy's C. oculatus. What the latter may in reality be is 

 an uncertainty to me at present, for I cannot identify any specimen 

 in the British Museum with it. 



119. CMton (Chitonellus) burrowi. 

 Chitonellus larvseformis, Heeve (non Burrow), Conch. Icon. fig. 3. 



Hab. Port Molle {Goppinger) ; Port Adelaide {Reeve). 



This curious species is known by the small size of the valves, the 

 remoteness from one another of the fourth, fifth, and sixth, and the 

 excessively short and densely packed spines on the mantle. The 

 single specimen in spirit, from Port Molle, is of a buff colour, 

 copiously mottled with green : this accords with a specimen (also 

 in spirit) mentioned by Reeve, collected by Capt. Belcher in the 

 Straits of Macassar. 



The dried specimens are greyish, more or less rose-tinted. 



The sculpture of the valves is very like that of C. striatus, consist- 

 ing of a central smoothish ridge, with two or three finer and more 

 or less wrinkled ones on each side, the front valve of course being 

 wrinkled throughout and lacking the central smooth ridge. They 

 are yellowish at the mucro or posteriorly, and pinkish red in front. 

 The plates of insertion are like those of C. striatus, and of a pale 

 greenish colour. 



