Among the newly collected material from the Inversand pit is a singular avian humerus that cannot be assigned to the Graculavidae or to any other known family, fossil or modern. Although it is generally inadvisable to name even Paleogene birds on single elements, to say nothing of Cretaceous ones, the specimen under consideration here is superior to any of the other avian fossils yet collected from the Cretaceous of New Jersey, both in preservation and in diagnostic qualities, and it would seem incongruous to leave it innominate when practically all the other fragments from the same deposits have received names. [Illustration: Figure 9.--Miscellaneous elements, _a_, _Palaeotringa littoralis?_ (NJSM 11303), distal end of left humerus, palmar view; _b_, Graculavidae, genus and species indeterminate (NJSM 11302), distal end of left humerus, palmar view; _c_, proximal end of radius associated with _b_; _d_, _Graculavus velox?_ (NJSM 11854), right carpometacarpus; _e,f_, Procellariiformes?, genus and species indeterminate (ANSP 15713), distal end of left ulna (_e_, external view;/dorsal view); _g_, Aves, incertae sedis (NJSM 12119), distal end of left femur, posterior view. (_a,b,c,d_, × 2; _e,f,g_, × 5; specimens coated with ammonium chloride to enhance detail.)] The most distinctive features of this specimen are the deep brachial depression and the incipient ectepicondylar spur, thus calling to mind both the Lari (Charadriiformes) and the Procellariiformes among modern birds. Among the Pelecaniformes it also bears a resemblance to the Phaethontidae and especially to the Eocene frigatebird _Limnofregata_ (Fregatidae) (Olson, 1977). =Family Tytthostonychidae, new family= Type Genus.--_Tytthostonyx_, new genus. Included Genera.--Type genus only. Diagnosis.--Differs from the Lari and other Charadriiformes in (1) the low, narrow head; (2) the very large, long pectoral crest; (3) the virtual absence of the incisura capitis or any excavation for M. coracobrachialis cranialis; and (4) the shallow, indistinct tricipital grooves. It agrees with the Procellariiformes and differs from _Phaethon_ and _Limnofregata_ in characters 2 and 4, and in the large, deeply excavated brachial depression. The ectepicondylar spur is better developed than in any of the Pelecaniformes but not as well developed as in the Procellariiformes. The apparently very broad pectoral crest extends much farther distally than in any of the Procellariiformes or even in _Limnofregata_, to which the fossil is somewhat more similar in this respect. Tytthostonyx differs from any of the taxa compared in having the ventral condyle very rounded, extending distally well past the dorsal condyle. =Genus _Tytthostonyx_, new genus= Type-Species.--_Tytthostonyx glauconiticus_, new species. Included Species.--Type species only. Diagnosis.--As for the family.