424 MR. A. D. MICHAEL ON ACARINA FROM ALGERIA. [Juiie 3, 



Cephaloihorax. — The plate on the dorsum of the rostrum is not 

 carried nearly so far forward as in C. echinipes ; it allows almost the 

 ■whole of the palpus to be seen from the dorsal aspect projecting 

 beyond the rostrum. The palpi arc very large and are dark and 

 chitinized, the penultimate joint very large, the ultimate provided 

 ■with a strong claw or spine, the palpus also bears several large 

 spatulate hairs ; the median portion of the rostral plate is depressed 

 and marked with several parallel, straight, longitudinal lines. This 

 central portion is bordered by a large raised ridge or roll on each 

 side ; the ridges are narrow anteriorly, ■where they nearly meet, and 

 gradually thicken and become more separated towards their 

 posterior ends, ■which are suddenly thickened and turned inward. 

 These ridges are thickly set ■with stout, very curved, opaque white 

 hairs which are extremely conspicuous. The chitinizing of the rest 

 of the body hardly assumes the form of distinct plates. The median 

 portion of the cephalothorax behind the rostrum is raised, forming 

 three large rough lobes. There are two long spatulate hairs on 

 each side of each lobe, thus forming two longitudinal lines ; they are 

 much longer and less spatulate than those on C. echinipes. All 

 round these lobes is a deep depressed trench, showing the striated 

 skin but little chitinized ; outside this laterally is a raised chitinized 

 margin composed of three lobes on each side, and a fourth lobe con- 

 tinues on to the posterior margin of the cephalothorax ; these lobes 

 all bear spatulate hairs similar in character to those on the central 

 lobes. The posterior margin is bordered with hairs corresponding 

 to those described below as bordering the abdomen. The eyes are 

 two on each side, placed as in C. echinipes, but rather more pro- 

 jecting. 



Legs very similar to those of C. echinipes, but the spines on the 

 femora of the first pair are more curved. The claws are didactyle, 

 but the two claws of each pair are very unequal, one claw being 

 strong, thick at the base, and slightly brown ; the other very small 

 and short, on some of the legs quite rudimentary. 



Abdomen (if this be really the division of the body) only pro- 

 jecting a comparatively short distance behind the cephalothorax, 

 and decidedly lower in level, so that the hairs on the hind margin 

 of the cephalothorax stand free above it. The hind margin is 

 divided into two flat lobes, being thus indented at the median line ; 

 it is bordered by a close line of large spatulate hairs, of which some 

 are markedly larger than others. The arrangement of the sizes is 

 definite : starting from the median line -we find, on each side, first 

 three small hairs, then a large one, then two small, then one large, 

 and then two more small. All these hairs, and indeed all the 

 spatulate hairs, both on the body and legs, are opaque white, 

 giving the creature a very singular and conspicuous appearance. 



I was only able to obtain one specimen of this species, which was 

 found in moss in the forest of Ain Beida, near Algiers. I doubt if 

 it be quite mature. I therefore thought at first that it might possibly 

 be some young form of C. echinipes ; but Professor Berlese, of 

 Florence, has been kind enough to lend me all his specimens of that 



