34 Smith and Harget — St. George's Banks Dredgings. 



separated by a broad and deep, rounded sinus ; the dactyhis is not 

 so stout, and has the inner margin evenly curved and serrated. 



Length, from front of head to tip of telson, 5 5 to Y'o""'. 



I refer this species with some hesitation to Boeck's genus Xenoclea, 

 which is known to me only from the very short diagnosis of the genus 

 and of the single species X. Batei, given in his Crustacea Amphipoda 

 Borealia et Arctica, p. 155. " Pedes 3tii et 4ti paris articulo Imo 

 latissimo" of the generic diagnosis would scarcely apply to our 

 species, but in all the other generic characters it agrees perfectly, as 

 it does also with the diagnosis of the sub-family Photinoe, except 

 that the mandibles each bear six serrated spines instead of the usual 

 numbei-, four. 



Near Cultivator Shoal (haul J), 30 fathoms, soft, sandy bottom, 

 August 29 ; and on the northern side of George's Bank (haul q), 

 north latitude 42°, west longitude 67° 42', 45 fathoms, coarse sandy 

 bottom. Also, in 18 fathoms, off Watch Hill, Rhode Island. 



When first examining the alcoholic specimens of this species, I 

 noticed a peculiar opaque glandular structure filling a large portion 

 of the third and fourth pairs of thoracic legs, which in most, if not 

 all, the non-tul)e-building Amjihipoda are wholly occui)ied by muscles. 

 A further examination shows that the terminal segment (dactylus) in 

 these legs is not acute and claw-like, biit truncated at the tip and 

 apparently tubular. In this sjiecies, a large cylindrical portion of 

 the gland lies along each side of the long basal segment, and these 

 two portions uniting at the distal end pass through tlie ischial and 

 along the jiosterior side of the meral and carpal segments and doubt- 

 less connect with the tubular dactylus. (See Plate III, figure 3.) 

 There can be no doubt that these are the glands which secrete the 

 cement with which the tubes are built, and that these two pairs of 

 legs are specialized for that purpose. A hasty examination revealed 

 a similar structiu'e of the corresponding legs in Ainjy/iithoe macidata, 

 Ptilocheirus pinguis, Cerapus rubricomis, Byblis Gaimardi, and a 

 species of Ampelisca. In all these except the last two a very large 

 proportion of the gland is in the basal segment. In the Amphithoe 

 this segment is thickened and the gland is in the middle. In the 

 Cerapus it is very broad and almost entirely filled by the gland, with 

 only very slender muscles through the middle, and the orifice in the 

 dactylus is not at the very tip but sub-terminal on the posterior side. 

 In the Ptilocheirus the gland forms three longitudinal masses in the 

 basal segment and is also largely developed in the meral and carpal 

 segments. The dactylus is long and slender and the orifice sub-ter- 

 minal. In Ampelisca and Byhlis (which, like Saploops, are tube- 

 building genera) the meral segments of the specialized legs are nearly 



