16 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



near the tip. The terminal joint is short, narrowed beyond the cen- 

 ter, and bluntly rounded at the tip. There are four pairs of biramose 

 swimming legs, each ramus three-jointed, the endopod of the fourth 

 legs being shorter and narrower. The spines on the legs are flattened 

 dorso-ventrally and are shaped like broad daggers. The egg strings 

 are a little more than half the total length of the body, narrowed 

 anteriorly and bluntly rounded posteriorly. The eggs are large 

 and are not arranged in definite rows, with 75 to 80 in each string. 



Color (preserved material), a uniform grayish brown. 



Total length, exclusive of anal setae, 1 mm. Width of first thorax 

 segment, 0.55 mm. Length of egg strings, 0.55 mm. Length of anal 

 setae, 0.21 mm. 



(jamaicensis, a native of Jamaica). 



Remarks. — The genus Modiolicola was established by Aurivillius 

 for a copepod which he had found inside the common European 

 mussel, Modiolus vulgaris, and occasionally in the oyster, Mytilus 

 edulis. Canu afterwards recorded another species under the name 

 Modiolicola inermis. 



T. Scott and Sars have both given supplementary descriptions and 

 figures of the original type species. The present specimens agree 

 so well with those descriptions as to leave no doubt that they belong 

 to the same genus. The endopod of the fourth legs is distinctly 

 three-jointed; the terminal joint long and narrow and tipped with 

 two flattened spines. The second antennae are tipped with two 

 curved claws, with two long setae outside of them; and the last joint 

 of the maxilliped in the female is small, unarmed, and very bluntly 

 rounded. These are the type characters of the genus and yet there 

 are enough differences in the present species to distinguish them 

 from those thus far described. 



The most noticeable characters are the short and stout anal 

 laminae, with their long setae and the flattened daggerlike spines 

 on the swimming legs. Both of the previous species of the genus 

 were found in mollusks, while the present specimens came from an 

 ascidian. But it is worthy of note that there are numerous mussels on 

 the mangrove roots, interspersed among the ascidians, and it would 

 be quite possible for free-swimming copepods to pass from one to 

 the other. It is to be regretted that the mussels were not also 

 examined for copepods. 



