210 



Part III. — Twenty -fifth Annual Report 



with some doubt, to this genus, especially as only the females had at 

 that time been noticed. The discovery of additional specimens allowed 

 a more thorough examination to be made of the structure of the species, 

 and it then became evident that its place in Laophonte was untenable, 

 and this rendered its removal to another genus — Harrietella — necessary. 



But while the female of this species has been known for a number 

 of years, the male has apparently remained undescribed. I, therefore, in 

 the following additional notes on the species, include a short description 

 of the male form. 



The species is a very small one, the female being scarcely half a milli- 

 metre in length, but the male is still smaller. It is a demersal form, and, 

 like a number of other such forms, its distribution is somewhat restricted. 

 I have rarely noticed H. simulans among the numerous bottom forms 

 occasionally captured with the dredge, even at some of the more favour- 

 able collecting grounds in the Firths of Forth and Clyde ; yet when a 

 piece of decaying wood, the surface of which is perforated by boring 

 molluscs or crustaceans, is brought up in the dredge or trawl net, 

 numerous examples of this particular Copepod may be obtained living 

 apparently in the crevices of the wood. When the pieces cf decaying 

 wood are carefully removed from amongst the other debris and washed in 

 a bottle containing methylated spirits, and the sediment examined under 

 a hand lens, quite a number of little animals may sometimes be obtained. 



In Laophonte the body is usually of a narrow, oblong form., but in 

 Harrietella it is broadly ovate and considerably depressed ; and while in 

 Laophonte the female carries only one ovisac, there are two in Har- 

 rietella. In the structure of the mouth appendages — the mandibles, 

 maxillae, and maxillipeds — there is a fairly close resemblance between the 

 two genera, and the same may be said concerning the two pairs of 

 antennae and the first pair of thoracic feet. The second and third pairs 

 in both the male and female, and especially in the male, though in their 

 general structure somewhat reseniDling those of Laophonte, they are 

 distinctly more robust. In both pairs the inner branch is composed of 

 two sub-equal joints, the first being rather shorter than the other. In 

 the male, the inner branch of the second and third pairs, which does not 

 reach the end of the second joint of the outer branch, is furnished with 

 two apical setae. The outer branch is elongated and stout, and composed 

 of three joints of nearly equal length ; the first and second are each 

 provided with a single moderately-long spine on the outer margin, and 

 the third joint, which is furnished with a similar spine on the outer 

 edge, bears also three strong terminal spines (fig. 3 represents one of the 

 second pair of feet). The fourth pair in the male resembles that of the 

 female in having the inner branch short, narrow, and uni-articulated, 

 and provided with two short apical setae ; but while the outer branch in 

 the female is two-jointed, that of the male consists of three joints, the 

 first two being each provided with a moderately long and stout plumose 

 seta on the outer margin, and the third with four similar setae round 

 the distal extremity. The outer branch of the fourth pair in the male, 

 like the same pair in the female, is remarkably stout (fig. 4). 



The fifth pair in the male consists of an oblong basal joint, provided 

 with a spiniform seta on the inner distal angle and a setiferous appendage 

 on the outer, and a small one-jointed branch bearing a few plumose 

 bristles (fig. 5). 



In the male, the last two segments of the metasome, though nearly 

 uniform in width with those of the urosome, are distinctly narrower than 

 the preceding segments, and in this respect there is a marked difference 

 between the two sexes when seen from above. 



