28 FOSSIL MALACOSTRACOUS CRUSTACEA. 



I had ventured, in the absence of any very satisfactory evidence, to consider one of the 

 species about to be described as identical with the Dromilites of Professor Milne Edwards; 

 and Professor M'Coy, in his account of his " Basinotopus Lamarckii," has the following note.* 

 " On recognizing at first the anomurous nature of this fossil, I thought it might be the 

 generic type named Dromilites by Dr. Milne Edwards, in the number of ' l'lnstitut ' for 

 August 1837, from Sheppey; "but having lately had the pleasure of showing him the 

 specimen, I find that though clearly allied, they are yet distinct." Finding in the various 

 collections which I have examined, numerous specimens of a Crustacean, answering so far 

 the indication of Professor M'Coy, and whose evident affinity to the recent genus Dromia 

 led me to believe that it must be identical with Dromilites of Dr. Edwards, and probably, 

 also, with Dromia Buchlandii of the same author,! I wrote to that gentleman, and have 

 been favoured by him with the loan of a beautiful drawing of his specimen, and am thus 

 enabled to confirm my previous views as to the identity of the species with my own. 

 I shall, therefore, be enabled for the first time to offer a full description of this interesting 

 form ; and I am also compelled to include M'Coy's Basinotopus in the same genus, 

 which I am confident he would have done, had he had the opportunity of examining the 

 specimens now before me. 



The full description of the two known species of this genus will show that there can 

 be no doubt whatever that it is a truly anomurous form. This is shown not only by the 

 condition and situation of the fourth and fifth pairs of legs, but also by the existence 

 of the two small intercalary pieces forming the appendages to the sixth segment of 

 the abdomen, which, in their development, constitute the lateral elements of the caudal 

 organ in the Macrura, and in those aberrant forms of Anomura which approach them, 

 such as Porcellana and allied genera. 



Its relation to the recent genus Dromia is also very obvious and highly interesting. 

 The essential characters are, indeed, as far as can be judged by the specimens under 

 observation, so similar, as to indicate a very close affinity, and to justify its being placed 

 not only within the family Dromiadoe, but in close approximation to the typical genus. 

 The general form of the carapace (with the exception that in the recent genus the anterior 

 portion is the broader, whilst in the fossil form the reverse is the case), the direction 

 and termination of the front, the structure of the footjaws, that of the legs, even to 

 the denticulation of the claw, and that of the abdomen in each sex, exhibit this close 

 relation ; and there is another fact which confirms it in a very interesting manner, and 

 that is the minute puncta which, in both species, are found to pervade every part of 

 the surface of the body and limbs, excepting the extremities of the claws, proving that 

 both the species of this extinct genus, like every known species of Dromia, was covered 

 with hair, and that of a similar character. The appearance of these puncta is absolutely 



* 'Ann. Nat. Hist.,' 1849, p. 167. 

 f 'Hist, nat. des Crust.,' ii, pp. 178-9. 



